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</div> <div class="control"> <button class="button is-small is-link">Go</button> </div> </div> </form> </div> </div> <nav class="pagination is-small is-centered breathe-horizontal" role="navigation" aria-label="pagination"> <a href="" class="pagination-previous is-invisible">Previous </a> <a href="/search/?searchtype=author&query=Rossnagel%2C+K&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Rossnagel%2C+K&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Rossnagel%2C+K&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> </ul> </nav> <ol class="breathe-horizontal" start="1"> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.18758">arXiv:2410.18758</a> <span> [<a href="https://arxiv.org/pdf/2410.18758">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Resistively detected electron spin resonance and g factor in few-layer exfoliated MoS2 devices </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Sharma%2C+C+H">Chithra H. Sharma</a>, <a href="/search/cond-mat?searchtype=author&query=Parvangada%2C+A">Appanna Parvangada</a>, <a href="/search/cond-mat?searchtype=author&query=Tiemann%2C+L">Lars Tiemann</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Martin%2C+J">Jens Martin</a>, <a href="/search/cond-mat?searchtype=author&query=Blick%2C+R+H">Robert H. Blick</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2410.18758v1-abstract-short" style="display: inline;"> MoS2 has recently emerged as a promising material for enabling quantum devices and spintronic applications. In this context, the demonstration of resistively detected electron spin resonance (RD-ESR) and the determination and improved physical understanding of the g factor are of great importance. However, its application and RD-ESR studies have been limited so far by Schotttky or high-resistance… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.18758v1-abstract-full').style.display = 'inline'; document.getElementById('2410.18758v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.18758v1-abstract-full" style="display: none;"> MoS2 has recently emerged as a promising material for enabling quantum devices and spintronic applications. In this context, the demonstration of resistively detected electron spin resonance (RD-ESR) and the determination and improved physical understanding of the g factor are of great importance. However, its application and RD-ESR studies have been limited so far by Schotttky or high-resistance contacts to MoS2. Here, we exploit naturally n-doped few-layer MoS2 devices with ohmic tin (Sn) contacts that allow the electrical study of spin phenomena. Resonant excitation of electron spins and resistive detection is a possible path to exploit the spin effects in MoS2 devices. Using RD-ESR, we determine the g factor of few-layer MoS2 to be ~ 1.92 and observe that the g factor value is independent of the charge carrier density within the limits of our measurements. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.18758v1-abstract-full').style.display = 'none'; document.getElementById('2410.18758v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">4 figures, 7 pages</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.02018">arXiv:2410.02018</a> <span> [<a href="https://arxiv.org/pdf/2410.02018">pdf</a>, <a href="https://arxiv.org/format/2410.02018">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> </div> </div> <p class="title is-5 mathjax"> Charge-density-wave control by adatom manipulation and its effect on magnetic nanostructures </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=R%C3%BCtten%2C+L+M">Lisa M. R眉tten</a>, <a href="/search/cond-mat?searchtype=author&query=Liebhaber%2C+E">Eva Liebhaber</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Franke%2C+K+J">Katharina J. Franke</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2410.02018v1-abstract-short" style="display: inline;"> Charge-density waves (CDWs) are correlated states of matter, where the electronic density is modulated periodically as a consequence of electronic and phononic interactions. Often, CDW phases coexist with other correlated states, such as superconductivity, spin-density waves or Mott insulators. Controlling CDW phases may therefore enable the manipulation of the energy landscape of these interactin… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.02018v1-abstract-full').style.display = 'inline'; document.getElementById('2410.02018v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.02018v1-abstract-full" style="display: none;"> Charge-density waves (CDWs) are correlated states of matter, where the electronic density is modulated periodically as a consequence of electronic and phononic interactions. Often, CDW phases coexist with other correlated states, such as superconductivity, spin-density waves or Mott insulators. Controlling CDW phases may therefore enable the manipulation of the energy landscape of these interacting states. 2H-NbSe$_2$ is a prime example of a transition metal dichalcogenide (TMDC) hosting CDW order and superconductivity. The CDW is of incommensurate nature resulting in different CDW-to-lattice alignments at the atomic scale. Here, we use the tip of a scanning tunneling microscope (STM) to position adatoms on the surface and induce reversible switching of the CDW domains. We show that the domain structure critically affects other local interactions, namely the hybridization of Yu-Shiba-Rusinov (YSR) states, which arise from exchange interactions of magnetic Fe atoms with the superconductor. Our results suggest that CDW manipulation could also be used to introduce domain walls in coupled spin chains on superconductors, potentially also affecting topological superconductivity. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.02018v1-abstract-full').style.display = 'none'; document.getElementById('2410.02018v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2408.03750">arXiv:2408.03750</a> <span> [<a href="https://arxiv.org/pdf/2408.03750">pdf</a>, <a href="https://arxiv.org/format/2408.03750">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Superconductivity">cond-mat.supr-con</span> </div> </div> <p class="title is-5 mathjax"> Chirality in the Kagome Metal CsV$_3$Sb$_5$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Elmers%2C+H+J">H. J. Elmers</a>, <a href="/search/cond-mat?searchtype=author&query=Tkach%2C+O">O. Tkach</a>, <a href="/search/cond-mat?searchtype=author&query=Lytvynenko%2C+Y">Y. Lytvynenko</a>, <a href="/search/cond-mat?searchtype=author&query=Yogi%2C+P">P. Yogi</a>, <a href="/search/cond-mat?searchtype=author&query=Schmitt%2C+M">M. Schmitt</a>, <a href="/search/cond-mat?searchtype=author&query=Biswas%2C+D">D. Biswas</a>, <a href="/search/cond-mat?searchtype=author&query=Liu%2C+J">J. Liu</a>, <a href="/search/cond-mat?searchtype=author&query=Chernov%2C+S+V">S. V. Chernov</a>, <a href="/search/cond-mat?searchtype=author&query=Hoesch%2C+M">M. Hoesch</a>, <a href="/search/cond-mat?searchtype=author&query=Kutnyakhov%2C+D">D. Kutnyakhov</a>, <a href="/search/cond-mat?searchtype=author&query=Wind%2C+N">N. Wind</a>, <a href="/search/cond-mat?searchtype=author&query=Wenthaus%2C+L">L. Wenthaus</a>, <a href="/search/cond-mat?searchtype=author&query=Scholz%2C+M">M. Scholz</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">K. Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Gloskovskii%2C+A">A. Gloskovskii</a>, <a href="/search/cond-mat?searchtype=author&query=Schlueter%2C+C">C. Schlueter</a>, <a href="/search/cond-mat?searchtype=author&query=Winkelmann%2C+A">A. Winkelmann</a>, <a href="/search/cond-mat?searchtype=author&query=Haghighirad%2C+A+-">A. -A. Haghighirad</a>, <a href="/search/cond-mat?searchtype=author&query=Lee%2C+T+-">T. -L. Lee</a>, <a href="/search/cond-mat?searchtype=author&query=Sing%2C+M">M. Sing</a>, <a href="/search/cond-mat?searchtype=author&query=Claessen%2C+R">R. Claessen</a>, <a href="/search/cond-mat?searchtype=author&query=Tacon%2C+M+L">M. Le Tacon</a>, <a href="/search/cond-mat?searchtype=author&query=Demsar%2C+J">J. Demsar</a>, <a href="/search/cond-mat?searchtype=author&query=Schonhense%2C+G">G. Schonhense</a>, <a href="/search/cond-mat?searchtype=author&query=Fedchenko%2C+O">O. Fedchenko</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2408.03750v1-abstract-short" style="display: inline;"> Using x-ray photoelectron diffraction (XPD) and angle-resolved photoemission spectroscopy, we study photoemission intensity changes related to changes in the geometric and electronic structure in the kagome metal CsV$_3$Sb$_5$ upon transition to an unconventional charge density wave (CDW) state. The XPD patterns reveal the presence of a chiral atomic structure in the CDW phase. Furthermore, using… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.03750v1-abstract-full').style.display = 'inline'; document.getElementById('2408.03750v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2408.03750v1-abstract-full" style="display: none;"> Using x-ray photoelectron diffraction (XPD) and angle-resolved photoemission spectroscopy, we study photoemission intensity changes related to changes in the geometric and electronic structure in the kagome metal CsV$_3$Sb$_5$ upon transition to an unconventional charge density wave (CDW) state. The XPD patterns reveal the presence of a chiral atomic structure in the CDW phase. Furthermore, using circularly polarized x-rays, we have found a pronounced non-trivial circular dichroism in the angular distribution of the valence band photoemission in the CDW phase, indicating a chirality of the electronic structure. This observation is consistent with the proposed orbital loop current order. In view of a negligible spontaneous Kerr signal in recent magneto-optical studies, the results suggest an antiferromagnetic coupling of the orbital magnetic moments along the $c$-axis. While the inherent structural chirality may also induce circular dichroism, the observed asymmetry values seem to be too large in the case of the weak structural distortions caused by the CDW. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.03750v1-abstract-full').style.display = 'none'; document.getElementById('2408.03750v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2407.19404">arXiv:2407.19404</a> <span> [<a href="https://arxiv.org/pdf/2407.19404">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Non-equilibrium States and Interactions in the Topological Insulator and Topological Crystalline Insulator Phases of NaCd4As3 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Kafle%2C+T+R">Tika R Kafle</a>, <a href="/search/cond-mat?searchtype=author&query=Zhang%2C+Y">Yingchao Zhang</a>, <a href="/search/cond-mat?searchtype=author&query=Wang%2C+Y">Yi-yan Wang</a>, <a href="/search/cond-mat?searchtype=author&query=Shi%2C+X">Xun Shi</a>, <a href="/search/cond-mat?searchtype=author&query=Li%2C+N">Na Li</a>, <a href="/search/cond-mat?searchtype=author&query=Sapkota%2C+R">Richa Sapkota</a>, <a href="/search/cond-mat?searchtype=author&query=Thurston%2C+J">Jeremy Thurston</a>, <a href="/search/cond-mat?searchtype=author&query=You%2C+W">Wenjing You</a>, <a href="/search/cond-mat?searchtype=author&query=Gao%2C+S">Shunye Gao</a>, <a href="/search/cond-mat?searchtype=author&query=Dong%2C+Q">Qingxin Dong</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Chen%2C+G">Gen-Fu Chen</a>, <a href="/search/cond-mat?searchtype=author&query=Freericks%2C+J+K">James K Freericks</a>, <a href="/search/cond-mat?searchtype=author&query=Kapteyn%2C+H+C">Henry C Kapteyn</a>, <a href="/search/cond-mat?searchtype=author&query=Murnane%2C+M+M">Margaret M Murnane</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2407.19404v2-abstract-short" style="display: inline;"> Topological materials are of great interest because they can support metallic edge or surface states that are robust against perturbations, with the potential for technological applications. Here we experimentally explore the light-induced non-equilibrium properties of two distinct topological phases in NaCd4As3: a topological crystalline insulator (TCI) phase and a topological insulator (TI) phas… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.19404v2-abstract-full').style.display = 'inline'; document.getElementById('2407.19404v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2407.19404v2-abstract-full" style="display: none;"> Topological materials are of great interest because they can support metallic edge or surface states that are robust against perturbations, with the potential for technological applications. Here we experimentally explore the light-induced non-equilibrium properties of two distinct topological phases in NaCd4As3: a topological crystalline insulator (TCI) phase and a topological insulator (TI) phase. This material has surface states that are protected by mirror symmetry in the TCI phase at room temperature, while it undergoes a structural phase transition to a TI phase below 200 K. After exciting the TI phase by an ultrafast laser pulse, we observe a leading band edge shift of >150 meV, that slowly builds up and reaches a maximum after ~0.6 ps, and that persists for ~8 ps. The slow rise time of the excited electron population and electron temperature suggests that the electronic and structural orders are strongly coupled in this TI phase. It also suggests that the directly excited electronic states and the probed electronic states are weakly coupled. Both couplings are likely due to a partial relaxation of the lattice distortion, which is known to be associated with the TI phase. In contrast, no distinct excited state is observed in the TCI phase immediately or after photoexcitation, which we attribute to the low density of states and phase space available near the Fermi level. Our results show how ultrafast laser excitation can reveal the distinct excited states and interactions in phase-rich topological materials. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2407.19404v2-abstract-full').style.display = 'none'; document.getElementById('2407.19404v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 August, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 28 July, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">21 pages, 9 figures, added theoretical insight in the discussion section and modified abstract, corrected typos and rephrased sentences, results and figures unchanged, added a co-author involved in sample preparation</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2406.02408">arXiv:2406.02408</a> <span> [<a href="https://arxiv.org/pdf/2406.02408">pdf</a>, <a href="https://arxiv.org/format/2406.02408">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> </div> <p class="title is-5 mathjax"> Anomalous 4$f$ fine structure in TmSe$_{1-x}$Te$_x$ across the metal-insulator transition </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Min%2C+C+-">C. -H. Min</a>, <a href="/search/cond-mat?searchtype=author&query=M%C3%BCller%2C+S">S. M眉ller</a>, <a href="/search/cond-mat?searchtype=author&query=Choi%2C+W+J">W. J. Choi</a>, <a href="/search/cond-mat?searchtype=author&query=Dudy%2C+L">L. Dudy</a>, <a href="/search/cond-mat?searchtype=author&query=Zabolotny%2C+V">V. Zabolotny</a>, <a href="/search/cond-mat?searchtype=author&query=Heber%2C+M">M. Heber</a>, <a href="/search/cond-mat?searchtype=author&query=Denlinger%2C+J+D">J. D. Denlinger</a>, <a href="/search/cond-mat?searchtype=author&query=Kang%2C+C+-">C. -J. Kang</a>, <a href="/search/cond-mat?searchtype=author&query=Kall%C3%A4ne%2C+M">M. Kall盲ne</a>, <a href="/search/cond-mat?searchtype=author&query=Wind%2C+N">N. Wind</a>, <a href="/search/cond-mat?searchtype=author&query=Scholz%2C+M">M. Scholz</a>, <a href="/search/cond-mat?searchtype=author&query=Lee%2C+T+L">T. L. Lee</a>, <a href="/search/cond-mat?searchtype=author&query=Schlueter%2C+C">C. Schlueter</a>, <a href="/search/cond-mat?searchtype=author&query=Gloskovskii%2C+A">A. Gloskovskii</a>, <a href="/search/cond-mat?searchtype=author&query=Rienks%2C+E+D+L">E. D. L. Rienks</a>, <a href="/search/cond-mat?searchtype=author&query=Hinkov%2C+V">V. Hinkov</a>, <a href="/search/cond-mat?searchtype=author&query=Bentmann%2C+H">H. Bentmann</a>, <a href="/search/cond-mat?searchtype=author&query=Kwon%2C+Y+S">Y. S. Kwon</a>, <a href="/search/cond-mat?searchtype=author&query=Reinert%2C+F">F. Reinert</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">K. Rossnagel</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2406.02408v1-abstract-short" style="display: inline;"> Hybridization between localized 4$f$ and itinerant 5$d$6$s$ states in heavy fermion compounds is a well-studied phenomenon and commonly captured by the paradigmatic Anderson model. However, the investigation of additional electronic interactions, beyond the standard Anderson model, has been limited, despite their predicted important role in the exotic quasiparticle formation in mixed-valence syste… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.02408v1-abstract-full').style.display = 'inline'; document.getElementById('2406.02408v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.02408v1-abstract-full" style="display: none;"> Hybridization between localized 4$f$ and itinerant 5$d$6$s$ states in heavy fermion compounds is a well-studied phenomenon and commonly captured by the paradigmatic Anderson model. However, the investigation of additional electronic interactions, beyond the standard Anderson model, has been limited, despite their predicted important role in the exotic quasiparticle formation in mixed-valence systems. We investigate the 4$f$ states in TmSe$_{1-x}$Te$_x$ throughout a semimetal-insulator phase transition, which drastically varies the interactions related to the 4$f$ states. Using synchrotron-based hard x-ray and extreme ultraviolet photoemission spectroscopy, we resolve subtle peak splitting in the 4$f$ peaks near the Fermi level in the mixed-valent semimetal phase. The separation is enhanced by several tens of meV by increasing the lattice parameter by a few percent. Our results elucidate the evolving nature of the 4$f$ state across the phase transition, and provide direct experimental evidence for electronic interactions beyond the standard Anderson model in mixed-valence systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.02408v1-abstract-full').style.display = 'none'; document.getElementById('2406.02408v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">5 pages, 4 figures for the main text, 6 pages and 5 figures for the supplementary</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2405.20872">arXiv:2405.20872</a> <span> [<a href="https://arxiv.org/pdf/2405.20872">pdf</a>, <a href="https://arxiv.org/format/2405.20872">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> </div> </div> <p class="title is-5 mathjax"> Ultrafast optical switching to a heterochiral charge-density wave state </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Huang%2C+W+C">Wayne Cheng-Wei Huang</a>, <a href="/search/cond-mat?searchtype=author&query=Mu%2C+S">Sai Mu</a>, <a href="/search/cond-mat?searchtype=author&query=von+Witte%2C+G">Gevin von Witte</a>, <a href="/search/cond-mat?searchtype=author&query=Li%2C+Y+S">Yanshuo Sophie Li</a>, <a href="/search/cond-mat?searchtype=author&query=Kurtz%2C+F">Felix Kurtz</a>, <a href="/search/cond-mat?searchtype=author&query=Hung%2C+S">Sheng-Hsiung Hung</a>, <a href="/search/cond-mat?searchtype=author&query=Jeng%2C+H">Horng-Tay Jeng</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Horstmann%2C+J+G">Jan Gerrit Horstmann</a>, <a href="/search/cond-mat?searchtype=author&query=Ropers%2C+C">Claus Ropers</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2405.20872v1-abstract-short" style="display: inline;"> Optical control of correlated electronic states promises unprecedented tunability of novel functional materials. Tailored optical excitations can steer a system along non-equilibrium pathways to metastable states with specific structural or electronic properties. A much-desired feature is the reproducible and ultrafast switching to functional states. The light-induced hidden state of 1T-TaS$_{2}$,… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.20872v1-abstract-full').style.display = 'inline'; document.getElementById('2405.20872v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.20872v1-abstract-full" style="display: none;"> Optical control of correlated electronic states promises unprecedented tunability of novel functional materials. Tailored optical excitations can steer a system along non-equilibrium pathways to metastable states with specific structural or electronic properties. A much-desired feature is the reproducible and ultrafast switching to functional states. The light-induced hidden state of 1T-TaS$_{2}$, with its strongly enhanced conductivity and exceptionally long lifetime, represents a unique model system for studying the switching of correlated electronic states using femtosecond optical stimuli. However, despite intense investigation, the switching mechanism and the structural origins of the distinctive electronic properties of the hidden state have not been fully uncovered. Here, we use surface-sensitive electron diffraction in combination with a femtosecond optical quench to reveal coexistent charge-density wave chiralities as a new structural feature of the hidden state. We find that a single-pulse optical quench produces a state with long-range structural order and different weights of the two chiral enantiomorphs of the charge-density wave. Harnessing a double-pulse optical quench, we trace the origin of the mixed chirality to the transient electronic excitation of the host crystal. The coexistent long-range-order of both chiralities suggests the presence of extended heterochiral charge-density wave interfaces, which results in a higher-level, fractal-type moir茅 superstructure. Density functional theory simulations for such a charge-density wave moir茅 superstructure reveal multiple flat bands, Dirac cones, and a kagome electronic subsystem around the Fermi energy. Our findings shed light on novel electronic properties gained by chiral interface engineering, and create avenues for light-induced moir茅 superstructures in quasi-two-dimensional materials. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.20872v1-abstract-full').style.display = 'none'; document.getElementById('2405.20872v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 31 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.16513">arXiv:2404.16513</a> <span> [<a href="https://arxiv.org/pdf/2404.16513">pdf</a>, <a href="https://arxiv.org/format/2404.16513">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Superconductivity">cond-mat.supr-con</span> </div> </div> <p class="title is-5 mathjax"> Wave-function engineering on superconducting substrates: Chiral Yu-Shiba-Rusinov molecules </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=R%C3%BCtten%2C+L+M">Lisa M. R眉tten</a>, <a href="/search/cond-mat?searchtype=author&query=Schmid%2C+H">Harald Schmid</a>, <a href="/search/cond-mat?searchtype=author&query=Liebhaber%2C+E">Eva Liebhaber</a>, <a href="/search/cond-mat?searchtype=author&query=Franceschi%2C+G">Giada Franceschi</a>, <a href="/search/cond-mat?searchtype=author&query=Yazdani%2C+A">Ali Yazdani</a>, <a href="/search/cond-mat?searchtype=author&query=Reecht%2C+G">Gael Reecht</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=von+Oppen%2C+F">Felix von Oppen</a>, <a href="/search/cond-mat?searchtype=author&query=Franke%2C+K+J">Katharina J. Franke</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2404.16513v1-abstract-short" style="display: inline;"> Magnetic adatoms on superconductors give rise to Yu-Shiba-Rusinov (YSR) states that hold considerable interest for the design of topological superconductivity. Here, we show that YSR states are also an ideal platform to engineer structures with intricate wave-function symmetries. We assemble structures of iron atoms on the quasi-two-dimensional superconductor $2H$-NbSe$_2$. The Yu-Shiba-Rusinov wa… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.16513v1-abstract-full').style.display = 'inline'; document.getElementById('2404.16513v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.16513v1-abstract-full" style="display: none;"> Magnetic adatoms on superconductors give rise to Yu-Shiba-Rusinov (YSR) states that hold considerable interest for the design of topological superconductivity. Here, we show that YSR states are also an ideal platform to engineer structures with intricate wave-function symmetries. We assemble structures of iron atoms on the quasi-two-dimensional superconductor $2H$-NbSe$_2$. The Yu-Shiba-Rusinov wave functions of individual atoms extend over several nanometers enabling hybridization even at large adatom spacing. We show that the substrate can be exploited to deliberately break symmetries of the adatom structure in ways unachievable in the gas phase. We highlight this potential by designing chiral wave functions of triangular adatom structures confined within a plane. Our results significantly expand the range of interesting quantum states that can be engineered using arrays of magnetic adatoms on superconductors. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.16513v1-abstract-full').style.display = 'none'; document.getElementById('2404.16513v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2404.02952">arXiv:2404.02952</a> <span> [<a href="https://arxiv.org/pdf/2404.02952">pdf</a>, <a href="https://arxiv.org/format/2404.02952">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> </div> </div> <p class="title is-5 mathjax"> Chirality-Driven Orbital Angular Momentum and Circular Dichroism in CoSi </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Brinkman%2C+S+S">Stefanie Suzanne Brinkman</a>, <a href="/search/cond-mat?searchtype=author&query=Tan%2C+X+L">Xin Liang Tan</a>, <a href="/search/cond-mat?searchtype=author&query=Brekke%2C+B">Bj酶rnulf Brekke</a>, <a href="/search/cond-mat?searchtype=author&query=Mathisen%2C+A+C">Anders Christian Mathisen</a>, <a href="/search/cond-mat?searchtype=author&query=Finnseth%2C+%C3%98">脴yvind Finnseth</a>, <a href="/search/cond-mat?searchtype=author&query=Schenk%2C+R+J">Richard Justin Schenk</a>, <a href="/search/cond-mat?searchtype=author&query=Hagiwara%2C+K">Kenta Hagiwara</a>, <a href="/search/cond-mat?searchtype=author&query=Huang%2C+M">Meng-Jie Huang</a>, <a href="/search/cond-mat?searchtype=author&query=Buck%2C+J">Jens Buck</a>, <a href="/search/cond-mat?searchtype=author&query=Kall%C3%A4ne%2C+M">Matthias Kall盲ne</a>, <a href="/search/cond-mat?searchtype=author&query=Hoesch%2C+M">Moritz Hoesch</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Yang%2C+K+O">Kui-Hon Ou Yang</a>, <a href="/search/cond-mat?searchtype=author&query=Lin%2C+M">Minn-Tsong Lin</a>, <a href="/search/cond-mat?searchtype=author&query=Shu%2C+G">Guo-Jiun Shu</a>, <a href="/search/cond-mat?searchtype=author&query=Chen%2C+Y">Ying-Jiun Chen</a>, <a href="/search/cond-mat?searchtype=author&query=Tusche%2C+C">Christian Tusche</a>, <a href="/search/cond-mat?searchtype=author&query=Bentmann%2C+H">Hendrik Bentmann</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2404.02952v1-abstract-short" style="display: inline;"> Chiral crystals and molecules were recently predicted to form an intriguing platform for unconventional orbital physics. Here, we report the observation of chirality-driven orbital textures in the bulk electronic structure of CoSi, a prototype member of the cubic B20 family of chiral crystals. Using circular dichroism in soft X-ray angle-resolved photoemission, we demonstrate the formation of a bu… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.02952v1-abstract-full').style.display = 'inline'; document.getElementById('2404.02952v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2404.02952v1-abstract-full" style="display: none;"> Chiral crystals and molecules were recently predicted to form an intriguing platform for unconventional orbital physics. Here, we report the observation of chirality-driven orbital textures in the bulk electronic structure of CoSi, a prototype member of the cubic B20 family of chiral crystals. Using circular dichroism in soft X-ray angle-resolved photoemission, we demonstrate the formation of a bulk orbital-angular-momentum texture and monopole-like orbital-momentum locking that depends on crystal handedness. We introduce the intrinsic chiral circular dichroism, icCD, as a differential photoemission observable and a natural probe of chiral electron states. Our findings render chiral crystals promising for spin-orbitronics applications. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2404.02952v1-abstract-full').style.display = 'none'; document.getElementById('2404.02952v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 April, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">To be published in Physical Review Letters</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Report number:</span> QuSpin 2024 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2403.07452">arXiv:2403.07452</a> <span> [<a href="https://arxiv.org/pdf/2403.07452">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Superconductivity">cond-mat.supr-con</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/1367-2630/ad4206">10.1088/1367-2630/ad4206 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A compact approach to higher-resolution resonant inelastic X-ray scattering detection using photoelectrons </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Schunck%2C+J+O">Jan O. Schunck</a>, <a href="/search/cond-mat?searchtype=author&query=Buck%2C+J">Jens Buck</a>, <a href="/search/cond-mat?searchtype=author&query=Engel%2C+R+Y">Robin Y. Engel</a>, <a href="/search/cond-mat?searchtype=author&query=Kruse%2C+S+R">Simon R. Kruse</a>, <a href="/search/cond-mat?searchtype=author&query=Marotzke%2C+S">Simon Marotzke</a>, <a href="/search/cond-mat?searchtype=author&query=Scholz%2C+M">Markus Scholz</a>, <a href="/search/cond-mat?searchtype=author&query=Mahatha%2C+S+K">Sanjoy K. Mahatha</a>, <a href="/search/cond-mat?searchtype=author&query=Huang%2C+M">Meng-Jie Huang</a>, <a href="/search/cond-mat?searchtype=author&query=R%C3%B8nnow%2C+H+M">Henrik M. R酶nnow</a>, <a href="/search/cond-mat?searchtype=author&query=Dakovski%2C+G">Georgi Dakovski</a>, <a href="/search/cond-mat?searchtype=author&query=Hoesch%2C+M">Moritz Hoesch</a>, <a href="/search/cond-mat?searchtype=author&query=Kall%C3%A4ne%2C+M">Matthias Kall盲ne</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Beye%2C+M">Martin Beye</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2403.07452v1-abstract-short" style="display: inline;"> The detection of inelastically scattered soft X-rays with high energy resolution usually requires large grating spectrometers. Recently, photoelectron spectrometry for analysis of X-rays (PAX) has been rediscovered for modern spectroscopy experiments at synchrotron light sources. By converting scattered photons to electrons and using an electron energy analyser, the energy resolution for resonant… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.07452v1-abstract-full').style.display = 'inline'; document.getElementById('2403.07452v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2403.07452v1-abstract-full" style="display: none;"> The detection of inelastically scattered soft X-rays with high energy resolution usually requires large grating spectrometers. Recently, photoelectron spectrometry for analysis of X-rays (PAX) has been rediscovered for modern spectroscopy experiments at synchrotron light sources. By converting scattered photons to electrons and using an electron energy analyser, the energy resolution for resonant inelastic X-ray scattering (RIXS) becomes decoupled from the X-ray spot size and instrument length. In this work, we develop PAX towards high energy resolution using a modern photoemission spectroscopy setup studying Ba2Cu3O4Cl2 at the Cu L3-edge. We measure a momentum transfer range of 24% of the first Brillouin zone simultaneously. Our results hint at the observation of a magnon excitation below 100 meV energy transfer and show intensity variations related to the dispersion of dd-excitations. With dedicated setups, PAX can become an alternative to the best and largest RIXS instruments, while at the same time opening new opportunities to acquire RIXS at a range of momentum transfers simultaneously and combine it with angle-resolved photoemission spectroscopy in a single instrument. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2403.07452v1-abstract-full').style.display = 'none'; document.getElementById('2403.07452v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 March, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2402.10031">arXiv:2402.10031</a> <span> [<a href="https://arxiv.org/pdf/2402.10031">pdf</a>, <a href="https://arxiv.org/format/2402.10031">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> </div> </div> <p class="title is-5 mathjax"> Tomographic Imaging of Orbital Vortex Lines in Three-Dimensional Momentum Space </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Figgemeier%2C+T">T. Figgemeier</a>, <a href="/search/cond-mat?searchtype=author&query=%C3%9Cnzelmann%2C+M">M. 脺nzelmann</a>, <a href="/search/cond-mat?searchtype=author&query=Eck%2C+P">P. Eck</a>, <a href="/search/cond-mat?searchtype=author&query=Schusser%2C+J">J. Schusser</a>, <a href="/search/cond-mat?searchtype=author&query=Crippa%2C+L">L. Crippa</a>, <a href="/search/cond-mat?searchtype=author&query=Neu%2C+J+N">J. N. Neu</a>, <a href="/search/cond-mat?searchtype=author&query=Geldiyev%2C+B">B. Geldiyev</a>, <a href="/search/cond-mat?searchtype=author&query=Kagerer%2C+P">P. Kagerer</a>, <a href="/search/cond-mat?searchtype=author&query=Buck%2C+J">J. Buck</a>, <a href="/search/cond-mat?searchtype=author&query=Kall%C3%A4ne%2C+M">M. Kall盲ne</a>, <a href="/search/cond-mat?searchtype=author&query=Hoesch%2C+M">M. Hoesch</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">K. Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Siegrist%2C+T">T. Siegrist</a>, <a href="/search/cond-mat?searchtype=author&query=Lim%2C+L+-">L. -K. Lim</a>, <a href="/search/cond-mat?searchtype=author&query=Moessner%2C+R">R. Moessner</a>, <a href="/search/cond-mat?searchtype=author&query=Sangiovanni%2C+G">G. Sangiovanni</a>, <a href="/search/cond-mat?searchtype=author&query=Di+Sante%2C+D">D. Di Sante</a>, <a href="/search/cond-mat?searchtype=author&query=Reinert%2C+F">F. Reinert</a>, <a href="/search/cond-mat?searchtype=author&query=Bentmann%2C+H">H. Bentmann</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2402.10031v2-abstract-short" style="display: inline;"> We report the experimental discovery of orbital vortex lines in the three-dimensional (3D) band structure of a topological semimetal. Combining linear and circular dichroism in soft x-ray angle-resolved photoemission (SX-ARPES) with first-principles theory, we image the winding of atomic orbital angular momentum, thereby revealing - and determining the location of - lines of vorticity in full 3D m… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.10031v2-abstract-full').style.display = 'inline'; document.getElementById('2402.10031v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2402.10031v2-abstract-full" style="display: none;"> We report the experimental discovery of orbital vortex lines in the three-dimensional (3D) band structure of a topological semimetal. Combining linear and circular dichroism in soft x-ray angle-resolved photoemission (SX-ARPES) with first-principles theory, we image the winding of atomic orbital angular momentum, thereby revealing - and determining the location of - lines of vorticity in full 3D momentum space. Our observation of momentum-space vortex lines with quantized winding number establishes an analogue to real-space quantum vortices, for instance, in type-II superconductors and certain non-collinear magnets. These results establish multimodal dichroism in SX-ARPES as an approach to trace 3D orbital textures. Our present findings particularly constitute the first imaging of non-trivial quantum-phase winding at line nodes and may pave the way to new orbitronic phenomena in quantum materials <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.10031v2-abstract-full').style.display = 'none'; document.getElementById('2402.10031v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 20 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 15 February, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2402.07609">arXiv:2402.07609</a> <span> [<a href="https://arxiv.org/pdf/2402.07609">pdf</a>, <a href="https://arxiv.org/format/2402.07609">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> </div> <p class="title is-5 mathjax"> Self-stacked 1$\mathrm{T}$-1$\mathrm{H}$ layers in 6$\mathrm{R}$-NbSeTe and the emergence of charge and magnetic correlations due to ligand disorder </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Mahatha%2C+S+K">S. K. Mahatha</a>, <a href="/search/cond-mat?searchtype=author&query=Phillips%2C+J">J. Phillips</a>, <a href="/search/cond-mat?searchtype=author&query=Corral-Sertal%2C+J">J. Corral-Sertal</a>, <a href="/search/cond-mat?searchtype=author&query=Subires%2C+D">D. Subires</a>, <a href="/search/cond-mat?searchtype=author&query=Korshsunov%2C+A">A. Korshsunov</a>, <a href="/search/cond-mat?searchtype=author&query=Kar%2C+A">A. Kar</a>, <a href="/search/cond-mat?searchtype=author&query=Buck%2C+J">J. Buck</a>, <a href="/search/cond-mat?searchtype=author&query=Diekmann%2C+F">F. Diekmann</a>, <a href="/search/cond-mat?searchtype=author&query=Ivanov%2C+Y+P">Y. P. Ivanov</a>, <a href="/search/cond-mat?searchtype=author&query=Chuvilin%2C+A">A. Chuvilin</a>, <a href="/search/cond-mat?searchtype=author&query=Mondal%2C+D">D. Mondal</a>, <a href="/search/cond-mat?searchtype=author&query=Vobornik%2C+I">I. Vobornik</a>, <a href="/search/cond-mat?searchtype=author&query=Bosak%2C+A">A. Bosak</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">K. Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Pardo%2C+V">V. Pardo</a>, <a href="/search/cond-mat?searchtype=author&query=Fumega%2C+A+O">Adolfo O. Fumega</a>, <a href="/search/cond-mat?searchtype=author&query=Blanco-Canosa%2C+S">S. Blanco-Canosa</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2402.07609v1-abstract-short" style="display: inline;"> The emergence of correlated phenomena arising from the combination of 1$\mathrm{T}$ and 1$\mathrm{H}$ van der Waals layers is the focus of intense research. Here, we synthesize a novel self-stacked 6$\mathrm{R}$ phase in NbSeTe, showing a perfect alternating 1T and 1H layers that grow coherently along the c-direction, as revealed by scanning transmission electron microscopy. Angle resolved photoem… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.07609v1-abstract-full').style.display = 'inline'; document.getElementById('2402.07609v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2402.07609v1-abstract-full" style="display: none;"> The emergence of correlated phenomena arising from the combination of 1$\mathrm{T}$ and 1$\mathrm{H}$ van der Waals layers is the focus of intense research. Here, we synthesize a novel self-stacked 6$\mathrm{R}$ phase in NbSeTe, showing a perfect alternating 1T and 1H layers that grow coherently along the c-direction, as revealed by scanning transmission electron microscopy. Angle resolved photoemission spectroscopy shows a mixed contribution of the trigonal and octahedral Nb bands to the Fermi level. Diffuse scattering reveals temperature-independent short-range charge fluctuations with propagation vector $\mathrm{q_{CO}}$=(0.25,0), derived from the condensation of a longitudinal mode in the 1T layer. We observe that ligand disorder quenches the formation of a charge density wave. Magnetization measurements suggest the presence of an inhomogeneous, short-range magnetic order, further supported by the absence of a clear phase transition in the specific heat. These experimental analyses in combination with \textit{ab initio} calculations indicate that the ground state of 6$\mathrm{R}$-NbSeTe is described by a statistical distribution of short-range charge-modulated and spin-correlated regions driven by ligand disorder. Our results devise a route to synthesize 1$\mathrm{T}$-1$\mathrm{H}$ self-stacked bulk heterostructures to study emergent phases of matter. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.07609v1-abstract-full').style.display = 'none'; document.getElementById('2402.07609v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 February, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">12 pages, including Supplementary Information. 4 figures + 6 supplementary figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.10084">arXiv:2401.10084</a> <span> [<a href="https://arxiv.org/pdf/2401.10084">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Multi-Mode Front Lens for Momentum Microscopy: Part II Experiments </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Tkach%2C+O">O. Tkach</a>, <a href="/search/cond-mat?searchtype=author&query=Fragkos%2C+S">S. Fragkos</a>, <a href="/search/cond-mat?searchtype=author&query=Nguyen%2C+Q">Q. Nguyen</a>, <a href="/search/cond-mat?searchtype=author&query=Chernov%2C+S">S. Chernov</a>, <a href="/search/cond-mat?searchtype=author&query=Scholz%2C+M">M. Scholz</a>, <a href="/search/cond-mat?searchtype=author&query=Wind%2C+N">N. Wind</a>, <a href="/search/cond-mat?searchtype=author&query=Babenkov%2C+S">S. Babenkov</a>, <a href="/search/cond-mat?searchtype=author&query=Fedchenko%2C+O">O. Fedchenko</a>, <a href="/search/cond-mat?searchtype=author&query=Lytvynenko%2C+Y">Y. Lytvynenko</a>, <a href="/search/cond-mat?searchtype=author&query=Zimmer%2C+D">D. Zimmer</a>, <a href="/search/cond-mat?searchtype=author&query=Hloskovskii%2C+A">A. Hloskovskii</a>, <a href="/search/cond-mat?searchtype=author&query=Kutnyakhov%2C+D">D. Kutnyakhov</a>, <a href="/search/cond-mat?searchtype=author&query=Pressacco%2C+F">F. Pressacco</a>, <a href="/search/cond-mat?searchtype=author&query=Dilling%2C+J">J. Dilling</a>, <a href="/search/cond-mat?searchtype=author&query=Bruckmeier%2C+L">L. Bruckmeier</a>, <a href="/search/cond-mat?searchtype=author&query=Heber%2C+M">M. Heber</a>, <a href="/search/cond-mat?searchtype=author&query=Scholz%2C+F">F. Scholz</a>, <a href="/search/cond-mat?searchtype=author&query=Sobota%2C+J">J. Sobota</a>, <a href="/search/cond-mat?searchtype=author&query=Koralek%2C+J">J. Koralek</a>, <a href="/search/cond-mat?searchtype=author&query=Sirica%2C+N">N. Sirica</a>, <a href="/search/cond-mat?searchtype=author&query=Kallmayer%2C+M">M. Kallmayer</a>, <a href="/search/cond-mat?searchtype=author&query=Hoesch%2C+M">M. Hoesch</a>, <a href="/search/cond-mat?searchtype=author&query=Schlueter%2C+C">C. Schlueter</a>, <a href="/search/cond-mat?searchtype=author&query=Odnodvorets%2C+L+V">L. V. Odnodvorets</a>, <a href="/search/cond-mat?searchtype=author&query=Mairesse%2C+Y">Y. Mairesse</a> , et al. (4 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2401.10084v2-abstract-short" style="display: inline;"> We have experimentally demonstrated different operating modes for the front lenses of the momentum microscopes described in Part I. Measurements at energies from vacuum UV at a high-harmonic generation (HHG)-based source to the soft and hard X-ray range at a synchrotron facility validated the results of theoretical ray-tracing calculations. The key element is a ring electrode concentric with the e… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.10084v2-abstract-full').style.display = 'inline'; document.getElementById('2401.10084v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.10084v2-abstract-full" style="display: none;"> We have experimentally demonstrated different operating modes for the front lenses of the momentum microscopes described in Part I. Measurements at energies from vacuum UV at a high-harmonic generation (HHG)-based source to the soft and hard X-ray range at a synchrotron facility validated the results of theoretical ray-tracing calculations. The key element is a ring electrode concentric with the extractor electrode, which can tailor the field in the gap. First, the gap-lens-assisted extractor mode reduces the field strength at the sample while mitigating image aberrations. This mode gave good results in all spectral ranges. Secondly, by compensating the field at the sample surface with a negative voltage at the ring electrode we can operate in zero-field mode, which is beneficial for operando experiments. Finally, higher negative voltages establish the repeller mode, which removes all slow electrons below a certain kinetic energy to eliminate the primary contribution to the space-charge interaction in pump-probe experiments. The switch from extractor to repeller mode is associated with a reduction in the k-field-of-view (10-20 % at hard-X-ray energies, increasing to ~50% at low energies). Real-space imaging also benefits from the new lens modes as confirmed by ToF-XPEEM imaging with 650 nm resolution. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.10084v2-abstract-full').style.display = 'none'; document.getElementById('2401.10084v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 18 January, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">22 pages, 9 figures, 56 references</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2309.01673">arXiv:2309.01673</a> <span> [<a href="https://arxiv.org/pdf/2309.01673">pdf</a>, <a href="https://arxiv.org/ps/2309.01673">ps</a>, <a href="https://arxiv.org/format/2309.01673">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Probing the Surface Polarization of Ferroelectric Thin Films by X-ray Standing Waves </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Hoang%2C+L+P">Le Phuong Hoang</a>, <a href="/search/cond-mat?searchtype=author&query=Spasojevic%2C+I">Irena Spasojevic</a>, <a href="/search/cond-mat?searchtype=author&query=Lee%2C+T">Tien-Lin Lee</a>, <a href="/search/cond-mat?searchtype=author&query=Pesquera%2C+D">David Pesquera</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Zegenhagen%2C+J">J枚rg Zegenhagen</a>, <a href="/search/cond-mat?searchtype=author&query=Catalan%2C+G">Gustau Catalan</a>, <a href="/search/cond-mat?searchtype=author&query=Vartanyants%2C+I+A">Ivan A. Vartanyants</a>, <a href="/search/cond-mat?searchtype=author&query=Scherz%2C+A">Andreas Scherz</a>, <a href="/search/cond-mat?searchtype=author&query=Mercurio%2C+G">Giuseppe Mercurio</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2309.01673v1-abstract-short" style="display: inline;"> Understanding the mechanisms underlying a stable polarization at the surface of ferroelectric thin films is of particular importance both from a fundamental point of view and to achieve control of the surface polarization itself. In this study, it is demonstrated that the X-ray standing wave technique allows the polarization near the surface of a ferroelectric thin film to be probed directly. The… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.01673v1-abstract-full').style.display = 'inline'; document.getElementById('2309.01673v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2309.01673v1-abstract-full" style="display: none;"> Understanding the mechanisms underlying a stable polarization at the surface of ferroelectric thin films is of particular importance both from a fundamental point of view and to achieve control of the surface polarization itself. In this study, it is demonstrated that the X-ray standing wave technique allows the polarization near the surface of a ferroelectric thin film to be probed directly. The X-ray standing wave technique is employed to determine, with picometer accuracy, Ti and Ba atomic positions near the surface of three differently strained $\mathrm{BaTiO_3}$ thin films grown on scandate substrates, with a $\mathrm{SrRuO_3}$ film as bottom electrode. This technique gives direct access to atomic positions, and thus to the local ferroelectric polarization, within the first 3 unit cells below the surface. By employing X-ray photoelectron spectroscopy, a detailed overview of the oxygen-containing species adsorbed on the surface, upon exposure to ambient conditions, is obtained. The combination of structural and spectroscopic information allows us to conclude on the most plausible mechanisms that stabilize the surface polarization in the three samples under study. The different amplitude and orientation of the local ferroelectric polarizations are associated with surface charges attributed to the type, amount and spatial distribution of the oxygen-containing adsorbates. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2309.01673v1-abstract-full').style.display = 'none'; document.getElementById('2309.01673v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 September, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2307.15392">arXiv:2307.15392</a> <span> [<a href="https://arxiv.org/pdf/2307.15392">pdf</a>, <a href="https://arxiv.org/format/2307.15392">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> </div> <p class="title is-5 mathjax"> Electronic structure and lattice dynamics of 1T-VSe$_2$: origin of the 3D-CDW </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Diego%2C+J">Josu Diego</a>, <a href="/search/cond-mat?searchtype=author&query=Subires%2C+D">D. Subires</a>, <a href="/search/cond-mat?searchtype=author&query=Said%2C+A+H">A. H. Said</a>, <a href="/search/cond-mat?searchtype=author&query=Chaney%2C+D+A">D. A. Chaney</a>, <a href="/search/cond-mat?searchtype=author&query=Korshunov%2C+A">A. Korshunov</a>, <a href="/search/cond-mat?searchtype=author&query=Garbarino%2C+G">G. Garbarino</a>, <a href="/search/cond-mat?searchtype=author&query=Diekmann%2C+F">F. Diekmann</a>, <a href="/search/cond-mat?searchtype=author&query=Mahatha%2C+K">K. Mahatha</a>, <a href="/search/cond-mat?searchtype=author&query=Pardo%2C+V">V. Pardo</a>, <a href="/search/cond-mat?searchtype=author&query=Strempfer%2C+J">J. Strempfer</a>, <a href="/search/cond-mat?searchtype=author&query=Perez%2C+P+J+B">Pablo J. Bereciartua Perez</a>, <a href="/search/cond-mat?searchtype=author&query=Francoual%2C+S">S. Francoual</a>, <a href="/search/cond-mat?searchtype=author&query=Popescu%2C+C">C. Popescu</a>, <a href="/search/cond-mat?searchtype=author&query=Tallarida%2C+M">M. Tallarida</a>, <a href="/search/cond-mat?searchtype=author&query=Dai%2C+J">J. Dai</a>, <a href="/search/cond-mat?searchtype=author&query=Bianco%2C+R">Raffaello Bianco</a>, <a href="/search/cond-mat?searchtype=author&query=Monacelli%2C+L">Lorenzo Monacelli</a>, <a href="/search/cond-mat?searchtype=author&query=Calandra%2C+M">Matteo Calandra</a>, <a href="/search/cond-mat?searchtype=author&query=Bosak%2C+A">A. Bosak</a>, <a href="/search/cond-mat?searchtype=author&query=Mauri%2C+F">Francesco Mauri</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">K. Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Fumega%2C+A+O">Adolfo O. Fumega</a>, <a href="/search/cond-mat?searchtype=author&query=Errea%2C+I">Ion Errea</a>, <a href="/search/cond-mat?searchtype=author&query=Blanco-Canosa%2C+S">S. Blanco-Canosa</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2307.15392v1-abstract-short" style="display: inline;"> In order to characterize in detail the charge density wave (CDW) transition of 1$T$-VSe$_2$, its electronic structure and lattice dynamics are comprehensively studied by means of x-ray diffraction, angle resolved photoemission (ARPES), diffuse and inelastic x-ray scattering (IXS), and state-of-the-art first principles density functional theory calculations. Resonant elastic x-ray scattering (REXS)… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.15392v1-abstract-full').style.display = 'inline'; document.getElementById('2307.15392v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2307.15392v1-abstract-full" style="display: none;"> In order to characterize in detail the charge density wave (CDW) transition of 1$T$-VSe$_2$, its electronic structure and lattice dynamics are comprehensively studied by means of x-ray diffraction, angle resolved photoemission (ARPES), diffuse and inelastic x-ray scattering (IXS), and state-of-the-art first principles density functional theory calculations. Resonant elastic x-ray scattering (REXS) does not show any resonant enhancement at either V or Se K-edges, indicating that the CDW peak describes a purely structural modulation of the electronic ordering. ARPES identifies (i) a pseudogap at T$>$T$_{CDW}$, which leads to a depletion of the density of states in the $ML-M'L'$ plane at T$<$T$_{CDW}$, and (ii) anomalies in the electronic dispersion reflecting a sizable impact of phonons on it. A diffuse scattering precursor, characteristic of soft phonons, is observed at room temperature (RT) and leads to the full collapse of the low-energy phonon ($蠅_1$) with propagation vector (0.25 0 -0.3) r.l.u. We show that the frequency and linewidth of this mode are anisotropic in momentum space, reflecting the momentum dependence of the electron-phonon interaction (EPI), hence demonstrating that the origin of the CDW is, to a much larger extent, due to the momentum dependence EPI with a small contribution from nesting. The pressure dependence of the $蠅_1$ soft mode remains nearly constant up to 13 GPa at RT, with only a modest softening before the transition to the high-pressure monoclinic $C2/m$ phase. The wide set of experimental data are well captured by our state-of-the art first-principles anharmonic calculations with the inclusion of van der Waals (vdW) corrections in the exchange-correlation functional. The description of the electronics and dynamics of VSe$_2$ reported here adds important pieces of information to the understanding of the electronic modulations of TMDs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.15392v1-abstract-full').style.display = 'none'; document.getElementById('2307.15392v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 28 July, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2307.05223">arXiv:2307.05223</a> <span> [<a href="https://arxiv.org/pdf/2307.05223">pdf</a>, <a href="https://arxiv.org/ps/2307.05223">ps</a>, <a href="https://arxiv.org/format/2307.05223">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Plasmonic polarons induced by alkali-atom deposition in hafnium disulfide (1$T$-HfS$_2$) </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Emeis%2C+C">Christoph Emeis</a>, <a href="/search/cond-mat?searchtype=author&query=Mahatha%2C+S+K">Sanjoy Kr Mahatha</a>, <a href="/search/cond-mat?searchtype=author&query=Rohlf%2C+S">Sebastian Rohlf</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Caruso%2C+F">Fabio Caruso</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2307.05223v1-abstract-short" style="display: inline;"> We combine ab-initio calculations based on many-body perturbation theory and the cumulant expansion with angle-resolved photoemission spectroscopy (ARPES) to quantify the electron-plasmon interaction in the highly-doped semiconducting transition metal dichalcogenide 1$T$-HfS$_2$. ARPES reveals the emergence of satellite spectral features in the vicinity of quasiparticle excitations at the bottom o… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.05223v1-abstract-full').style.display = 'inline'; document.getElementById('2307.05223v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2307.05223v1-abstract-full" style="display: none;"> We combine ab-initio calculations based on many-body perturbation theory and the cumulant expansion with angle-resolved photoemission spectroscopy (ARPES) to quantify the electron-plasmon interaction in the highly-doped semiconducting transition metal dichalcogenide 1$T$-HfS$_2$. ARPES reveals the emergence of satellite spectral features in the vicinity of quasiparticle excitations at the bottom of the conduction band, suggesting coupling to bosonic excitations with a characteristic energy of 200 meV. Our first-principles calculations of the photoemission spectral function reveal that these features can be ascribed to electronic coupling to carrier plasmons (doping-induced collective charge-density fluctuations). We further show that reduced screening at the surface enhances the electron-plasmon interaction and is primarily responsible for the emergence of plasmonic polarons. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.05223v1-abstract-full').style.display = 'none'; document.getElementById('2307.05223v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 11 July, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2306.10637">arXiv:2306.10637</a> <span> [<a href="https://arxiv.org/pdf/2306.10637">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Real-time observation of phonon-electron energy and angular momentum flow in laser-heated nickel </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Shokeen%2C+V">Vishal Shokeen</a>, <a href="/search/cond-mat?searchtype=author&query=Heber%2C+M">Michael Heber</a>, <a href="/search/cond-mat?searchtype=author&query=Kutnyakhov%2C+D">Dmytro Kutnyakhov</a>, <a href="/search/cond-mat?searchtype=author&query=Wang%2C+X">Xiaocui Wang</a>, <a href="/search/cond-mat?searchtype=author&query=Yaroslavtsev%2C+A">Alexander Yaroslavtsev</a>, <a href="/search/cond-mat?searchtype=author&query=Maldonado%2C+P">Pablo Maldonado</a>, <a href="/search/cond-mat?searchtype=author&query=Berritta%2C+M">Marco Berritta</a>, <a href="/search/cond-mat?searchtype=author&query=Wind%2C+N">Nils Wind</a>, <a href="/search/cond-mat?searchtype=author&query=Wenthaus%2C+L">Lukas Wenthaus</a>, <a href="/search/cond-mat?searchtype=author&query=Pressacco%2C+F">Federico Pressacco</a>, <a href="/search/cond-mat?searchtype=author&query=Min%2C+C">Chul-Hee Min</a>, <a href="/search/cond-mat?searchtype=author&query=Nissen%2C+M">Matz Nissen</a>, <a href="/search/cond-mat?searchtype=author&query=Mahatha%2C+S+K">Sanjoy K. Mahatha</a>, <a href="/search/cond-mat?searchtype=author&query=Dziarzhytski%2C+S">Siarhei Dziarzhytski</a>, <a href="/search/cond-mat?searchtype=author&query=Oppeneer%2C+P+M">Peter M. Oppeneer</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Elmers%2C+H">Hans-Joachim Elmers</a>, <a href="/search/cond-mat?searchtype=author&query=Sch%C3%B6nhense%2C+G">Gerd Sch枚nhense</a>, <a href="/search/cond-mat?searchtype=author&query=D%C3%BCrr%2C+H+A">Hermann A. D眉rr</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2306.10637v2-abstract-short" style="display: inline;"> Identifying the microscopic nature of non-equilibrium energy transfer mechanisms among electronic, spin and lattice degrees of freedom is central for understanding ultrafast phenomena such as manipulating magnetism on the femtosecond timescale. Here we use time and angle-resolved photoemission spectroscopy to go beyond the often-employed ensemble-averaged view of non-equilibrium dynamics in terms… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.10637v2-abstract-full').style.display = 'inline'; document.getElementById('2306.10637v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.10637v2-abstract-full" style="display: none;"> Identifying the microscopic nature of non-equilibrium energy transfer mechanisms among electronic, spin and lattice degrees of freedom is central for understanding ultrafast phenomena such as manipulating magnetism on the femtosecond timescale. Here we use time and angle-resolved photoemission spectroscopy to go beyond the often-employed ensemble-averaged view of non-equilibrium dynamics in terms of quasiparticle temperature evolutions. We show for ferromagnetic Ni that the non-equilibrium electron and spin dynamics display pronounced variations with electron momentum whereas the magnetic exchange interaction remains isotropic. This highlights the influence of lattice-mediated scattering processes and opens a pathway towards unraveling the still elusive microscopic mechanism of spin-lattice angular momentum transfer. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.10637v2-abstract-full').style.display = 'none'; document.getElementById('2306.10637v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 December, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 18 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2306.02170">arXiv:2306.02170</a> <span> [<a href="https://arxiv.org/pdf/2306.02170">pdf</a>, <a href="https://arxiv.org/format/2306.02170">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> </div> <p class="title is-5 mathjax"> Observation of time-reversal symmetry breaking in the band structure of altermagnetic RuO$_2$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Fedchenko%2C+O">O. Fedchenko</a>, <a href="/search/cond-mat?searchtype=author&query=Minar%2C+J">J. Minar</a>, <a href="/search/cond-mat?searchtype=author&query=Akashdeep%2C+A">A. Akashdeep</a>, <a href="/search/cond-mat?searchtype=author&query=D%27Souza%2C+S+W">S. W. D'Souza</a>, <a href="/search/cond-mat?searchtype=author&query=Vasilyev%2C+D">D. Vasilyev</a>, <a href="/search/cond-mat?searchtype=author&query=Tkach%2C+O">O. Tkach</a>, <a href="/search/cond-mat?searchtype=author&query=Odenbreit%2C+L">L. Odenbreit</a>, <a href="/search/cond-mat?searchtype=author&query=Nguyen%2C+Q+L">Q. L. Nguyen</a>, <a href="/search/cond-mat?searchtype=author&query=Kutnyakhov%2C+D">D. Kutnyakhov</a>, <a href="/search/cond-mat?searchtype=author&query=Wind%2C+N">N. Wind</a>, <a href="/search/cond-mat?searchtype=author&query=Wenthaus%2C+L">L. Wenthaus</a>, <a href="/search/cond-mat?searchtype=author&query=Scholz%2C+M">M. Scholz</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">K. Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Hoesch%2C+M">M. Hoesch</a>, <a href="/search/cond-mat?searchtype=author&query=Aeschlimann%2C+M">M. Aeschlimann</a>, <a href="/search/cond-mat?searchtype=author&query=Stadtmueller%2C+B">B. Stadtmueller</a>, <a href="/search/cond-mat?searchtype=author&query=Klaeui%2C+M">M. Klaeui</a>, <a href="/search/cond-mat?searchtype=author&query=Schoenhense%2C+G">G. Schoenhense</a>, <a href="/search/cond-mat?searchtype=author&query=Jakob%2C+G">G. Jakob</a>, <a href="/search/cond-mat?searchtype=author&query=Jungwirth%2C+T">T. Jungwirth</a>, <a href="/search/cond-mat?searchtype=author&query=Smejkal%2C+L">L. Smejkal</a>, <a href="/search/cond-mat?searchtype=author&query=Sinova%2C+J">J. Sinova</a>, <a href="/search/cond-mat?searchtype=author&query=Elmers%2C+H+J">H. J. Elmers</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2306.02170v1-abstract-short" style="display: inline;"> Altermagnets are an emerging third elementary class of magnets. Unlike ferromagnets, their distinct crystal symmetries inhibit magnetization while, unlike antiferromagnets, they promote strong spin polarization in the band structure. The corresponding unconventional mechanism of timereversal symmetry breaking without magnetization in the electronic spectra has been regarded as a primary signature… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.02170v1-abstract-full').style.display = 'inline'; document.getElementById('2306.02170v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2306.02170v1-abstract-full" style="display: none;"> Altermagnets are an emerging third elementary class of magnets. Unlike ferromagnets, their distinct crystal symmetries inhibit magnetization while, unlike antiferromagnets, they promote strong spin polarization in the band structure. The corresponding unconventional mechanism of timereversal symmetry breaking without magnetization in the electronic spectra has been regarded as a primary signature of altermagnetism, but has not been experimentally visualized to date. We directly observe strong time-reversal symmetry breaking in the band structure of altermagnetic RuO$_2$ by detecting magnetic circular dichroism in angle-resolved photoemission spectra. Our experimental results, supported by ab initio calculations, establish the microscopic electronic-structure basis for a family of novel phenomena and functionalities in fields ranging from topological matter to spintronics, that are based on the unconventional time-reversal symmetry breaking in altermagnets. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2306.02170v1-abstract-full').style.display = 'none'; document.getElementById('2306.02170v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2305.07773">arXiv:2305.07773</a> <span> [<a href="https://arxiv.org/pdf/2305.07773">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.21203/rs.3.rs-2599640/v1">10.21203/rs.3.rs-2599640/v1 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Multiplex movie of concerted rotation of molecules on a 2D material </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Baumg%C3%A4rtner%2C+K">Kiana Baumg盲rtner</a>, <a href="/search/cond-mat?searchtype=author&query=Nozaki%2C+M">Misa Nozaki</a>, <a href="/search/cond-mat?searchtype=author&query=Reuner%2C+M">Marvin Reuner</a>, <a href="/search/cond-mat?searchtype=author&query=Wind%2C+N">Nils Wind</a>, <a href="/search/cond-mat?searchtype=author&query=Haniuda%2C+M">Masato Haniuda</a>, <a href="/search/cond-mat?searchtype=author&query=Metzger%2C+C">Christian Metzger</a>, <a href="/search/cond-mat?searchtype=author&query=Heber%2C+M">Michael Heber</a>, <a href="/search/cond-mat?searchtype=author&query=Kutnyakhov%2C+D">Dmytro Kutnyakhov</a>, <a href="/search/cond-mat?searchtype=author&query=Pressacco%2C+F">Federico Pressacco</a>, <a href="/search/cond-mat?searchtype=author&query=Wenthaus%2C+L">Lukas Wenthaus</a>, <a href="/search/cond-mat?searchtype=author&query=Hara%2C+K">Keisuke Hara</a>, <a href="/search/cond-mat?searchtype=author&query=Min%2C+C">Chul-Hee Min</a>, <a href="/search/cond-mat?searchtype=author&query=Beye%2C+M">Martin Beye</a>, <a href="/search/cond-mat?searchtype=author&query=Reinert%2C+F">Friedrich Reinert</a>, <a href="/search/cond-mat?searchtype=author&query=Roth%2C+F">Friedrich Roth</a>, <a href="/search/cond-mat?searchtype=author&query=Mahatha%2C+S+K">Sanjoy Kr Mahatha</a>, <a href="/search/cond-mat?searchtype=author&query=Madsen%2C+A">Anders Madsen</a>, <a href="/search/cond-mat?searchtype=author&query=Wehling%2C+T">Tim Wehling</a>, <a href="/search/cond-mat?searchtype=author&query=Niki%2C+K">Kaori Niki</a>, <a href="/search/cond-mat?searchtype=author&query=Popova-Gorelova%2C+D">Daria Popova-Gorelova</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Scholz%2C+M">Markus Scholz</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2305.07773v1-abstract-short" style="display: inline;"> Function is dynamic and originates at atomic interfaces. Combining the degrees of freedom of molecules with the peculiar properties of 2D quantum materials can create novel functionality. Here, we report the manipulation and ultrafast imaging of a unidirectional gearing motion in molecules on a 2D quantum material. To visualize and disentangle the intertwined structural and electronic dynamics of… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.07773v1-abstract-full').style.display = 'inline'; document.getElementById('2305.07773v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2305.07773v1-abstract-full" style="display: none;"> Function is dynamic and originates at atomic interfaces. Combining the degrees of freedom of molecules with the peculiar properties of 2D quantum materials can create novel functionality. Here, we report the manipulation and ultrafast imaging of a unidirectional gearing motion in molecules on a 2D quantum material. To visualize and disentangle the intertwined structural and electronic dynamics of such a hybrid interface, we record a 'full molecular movie' by imaging the atomic positions, the evolution of the molecular orbital wavefunctions and the modification of electronic states of the substrate. In a multimodal investigation in a single setup, we disentangle dynamics in valence and core electrons of both the molecule and the surface with femtosecond and sub-氓ngstr枚m precision. The ultrafast rotational motion is fueled by the transfer of hot holes into the molecules that results in 'supercharging' of the film. As hot carriers move through the interface, we track a transient modification of the frontier molecular orbitals and observe a chiral symmetry breaking associated with local structural rearrangements. Our calculations show that the 'supercharging' changes the interfacial potential energy landscape and triggers the gearing motion. The experiment offers all-in-one imaging of the electronic, molecular orbital, chemical and structural dynamics during the flow of charge and energy across the hybrid interface. Our approach provides detailed dynamical information on the mechanism underlying surface-adsorbed molecular gears and enables tailoring novel functionalities in hybrid active matter. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2305.07773v1-abstract-full').style.display = 'none'; document.getElementById('2305.07773v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">19 pages, 6 figures</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2212.07148">arXiv:2212.07148</a> <span> [<a href="https://arxiv.org/pdf/2212.07148">pdf</a>, <a href="https://arxiv.org/ps/2212.07148">ps</a>, <a href="https://arxiv.org/format/2212.07148">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1088/1361-648X/aceedf">10.1088/1361-648X/aceedf <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Unconventional topological phase transition from semimetal to insulator in SnBi2Te4: Role of anomalous thermal expansion </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Dalui%2C+T+K">T. K. Dalui</a>, <a href="/search/cond-mat?searchtype=author&query=Das%2C+B">B. Das</a>, <a href="/search/cond-mat?searchtype=author&query=Barman%2C+C+K">C. K. Barman</a>, <a href="/search/cond-mat?searchtype=author&query=Ghose%2C+P+K">P. K. Ghose</a>, <a href="/search/cond-mat?searchtype=author&query=Sarma%2C+A">A. Sarma</a>, <a href="/search/cond-mat?searchtype=author&query=Mahatha%2C+S+K">S. K. Mahatha</a>, <a href="/search/cond-mat?searchtype=author&query=Diekmann%2C+F">F. Diekmann</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">K. Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Majumdar%2C+S">S. Majumdar</a>, <a href="/search/cond-mat?searchtype=author&query=Alam%2C+A">A. Alam</a>, <a href="/search/cond-mat?searchtype=author&query=Giri%2C+S">S. Giri</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2212.07148v1-abstract-short" style="display: inline;"> We propose SnBi2Te4 to be a novel candidate material exhibiting temperature (T) mediated transitions between rich topological phases. From a combined theoretical and experimental studies, we find that SnBi2Te4 goes from a low-T topological semimetallic phase to a high-T (room temperature) topological insulating phase via an intermediate topological metallic phase. Single crystals of SnBi2Te4 are c… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.07148v1-abstract-full').style.display = 'inline'; document.getElementById('2212.07148v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2212.07148v1-abstract-full" style="display: none;"> We propose SnBi2Te4 to be a novel candidate material exhibiting temperature (T) mediated transitions between rich topological phases. From a combined theoretical and experimental studies, we find that SnBi2Te4 goes from a low-T topological semimetallic phase to a high-T (room temperature) topological insulating phase via an intermediate topological metallic phase. Single crystals of SnBi2Te4 are characterized by various experimental probes including Synchrotron based X-ray diffraction, magnetoresistance, Hall effect, Seebeck coefficient, magnetization and angle-resolved photoemission spectroscopy (ARPES). X-ray diffraction data confirms an anomalous thermal expansion of the unit cell volume below 100 K, which significantly affects the bulk band structure and hence the transport properties, as confirmed by our density functional theory calculations. Simulated surface states at 15 K agree fairly well with our ARPES data and are found to be robust with varying T. This indirectly supports the experimentally observed paramagnetic singularity in the entire T-range. The proposed coexistence of rich topological phases is a rare occurrence, yet paves a fertile ground to tune various topological phases in a material driven by structural distortion. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2212.07148v1-abstract-full').style.display = 'none'; document.getElementById('2212.07148v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 December, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">pages 7, 3 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> J. Phys.: Condens. Matter 35, 465701 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2211.17008">arXiv:2211.17008</a> <span> [<a href="https://arxiv.org/pdf/2211.17008">pdf</a>, <a href="https://arxiv.org/format/2211.17008">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1063/4.0000206">10.1063/4.0000206 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Electron Dynamics at High-Energy Densities in Nickel from Non-linear Resonant X-ray Absorption Spectra </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Engel%2C+R+Y">Robin Y. Engel</a>, <a href="/search/cond-mat?searchtype=author&query=Alexander%2C+O">Oliver Alexander</a>, <a href="/search/cond-mat?searchtype=author&query=Atak%2C+K">Kaan Atak</a>, <a href="/search/cond-mat?searchtype=author&query=Bovensiepen%2C+U">Uwe Bovensiepen</a>, <a href="/search/cond-mat?searchtype=author&query=Buck%2C+J">Jens Buck</a>, <a href="/search/cond-mat?searchtype=author&query=Carley%2C+R">Robert Carley</a>, <a href="/search/cond-mat?searchtype=author&query=Cascella%2C+M">Michele Cascella</a>, <a href="/search/cond-mat?searchtype=author&query=Chardonnet%2C+V">Valentin Chardonnet</a>, <a href="/search/cond-mat?searchtype=author&query=Chiuzbaian%2C+G+S">Gheorghe Sorin Chiuzbaian</a>, <a href="/search/cond-mat?searchtype=author&query=David%2C+C">Christian David</a>, <a href="/search/cond-mat?searchtype=author&query=D%C3%B6ring%2C+F">Florian D枚ring</a>, <a href="/search/cond-mat?searchtype=author&query=Eschenlohr%2C+A">Andrea Eschenlohr</a>, <a href="/search/cond-mat?searchtype=author&query=Gerasimova%2C+N">Natalia Gerasimova</a>, <a href="/search/cond-mat?searchtype=author&query=de+Groot%2C+F">Frank de Groot</a>, <a href="/search/cond-mat?searchtype=author&query=Guyader%2C+L+L">Lo茂c Le Guyader</a>, <a href="/search/cond-mat?searchtype=author&query=Humphries%2C+O+S">Oliver S. Humphries</a>, <a href="/search/cond-mat?searchtype=author&query=Izquierdo%2C+M">Manuel Izquierdo</a>, <a href="/search/cond-mat?searchtype=author&query=Jal%2C+E">Emmanuelle Jal</a>, <a href="/search/cond-mat?searchtype=author&query=Kubec%2C+A">Adam Kubec</a>, <a href="/search/cond-mat?searchtype=author&query=Laarmann%2C+T">Tim Laarmann</a>, <a href="/search/cond-mat?searchtype=author&query=Lambert%2C+C">Charles-Henri Lambert</a>, <a href="/search/cond-mat?searchtype=author&query=L%C3%BCning%2C+J">Jan L眉ning</a>, <a href="/search/cond-mat?searchtype=author&query=Marangos%2C+J+P">Jonathan P. Marangos</a>, <a href="/search/cond-mat?searchtype=author&query=Mercadier%2C+L">Laurent Mercadier</a>, <a href="/search/cond-mat?searchtype=author&query=Mercurio%2C+G">Giuseppe Mercurio</a> , et al. (18 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2211.17008v1-abstract-short" style="display: inline;"> The pulse intensity from X-ray free-electron lasers (FELs) can create extreme excitation densities in solids, entering the regime of non-linear X-ray-matter interactions. We show L3-edge absorption spectra of metallic nickel thin films with fluences entering a regime where several X-ray photons are incident per absorption cross-section. Main features of the observed non-linear spectral changes are… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.17008v1-abstract-full').style.display = 'inline'; document.getElementById('2211.17008v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2211.17008v1-abstract-full" style="display: none;"> The pulse intensity from X-ray free-electron lasers (FELs) can create extreme excitation densities in solids, entering the regime of non-linear X-ray-matter interactions. We show L3-edge absorption spectra of metallic nickel thin films with fluences entering a regime where several X-ray photons are incident per absorption cross-section. Main features of the observed non-linear spectral changes are described with a predictive rate model for electron population dynamics during the pulse, utilizing a fixed density of states and tabulated ground-state properties. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.17008v1-abstract-full').style.display = 'none'; document.getElementById('2211.17008v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 30 November, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">The main text contains 5 pages and 4 figures, the total length including supplement is 14 pages, 7 figures and one table. See also the simultaneously submitted paper about the rate model</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2211.04265">arXiv:2211.04265</a> <span> [<a href="https://arxiv.org/pdf/2211.04265">pdf</a>, <a href="https://arxiv.org/format/2211.04265">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1107/S1600577523000619">10.1107/S1600577523000619 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Photon shot-noise limited transient absorption soft X-ray spectroscopy at the European XFEL </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Guyader%2C+L+L">Lo茂c Le Guyader</a>, <a href="/search/cond-mat?searchtype=author&query=Eschenlohr%2C+A">Andrea Eschenlohr</a>, <a href="/search/cond-mat?searchtype=author&query=Beye%2C+M">Martin Beye</a>, <a href="/search/cond-mat?searchtype=author&query=Schlotter%2C+W">William Schlotter</a>, <a href="/search/cond-mat?searchtype=author&query=D%C3%B6ring%2C+F">Florian D枚ring</a>, <a href="/search/cond-mat?searchtype=author&query=Carinan%2C+C">Cammille Carinan</a>, <a href="/search/cond-mat?searchtype=author&query=Hickin%2C+D">David Hickin</a>, <a href="/search/cond-mat?searchtype=author&query=Agarwal%2C+N">Naman Agarwal</a>, <a href="/search/cond-mat?searchtype=author&query=Boeglin%2C+C">Christine Boeglin</a>, <a href="/search/cond-mat?searchtype=author&query=Bovensiepen%2C+U">Uwe Bovensiepen</a>, <a href="/search/cond-mat?searchtype=author&query=Buck%2C+J">Jens Buck</a>, <a href="/search/cond-mat?searchtype=author&query=Carley%2C+R">Robert Carley</a>, <a href="/search/cond-mat?searchtype=author&query=Castoldi%2C+A">Andrea Castoldi</a>, <a href="/search/cond-mat?searchtype=author&query=D%27Elia%2C+A">Alessandro D'Elia</a>, <a href="/search/cond-mat?searchtype=author&query=Delitz%2C+J">Jan-Torben Delitz</a>, <a href="/search/cond-mat?searchtype=author&query=Ehsan%2C+W">Wajid Ehsan</a>, <a href="/search/cond-mat?searchtype=author&query=Engel%2C+R">Robin Engel</a>, <a href="/search/cond-mat?searchtype=author&query=Erdinger%2C+F">Florian Erdinger</a>, <a href="/search/cond-mat?searchtype=author&query=Fangohr%2C+H">Hans Fangohr</a>, <a href="/search/cond-mat?searchtype=author&query=Fischer%2C+P">Peter Fischer</a>, <a href="/search/cond-mat?searchtype=author&query=Fiorini%2C+C">Carlo Fiorini</a>, <a href="/search/cond-mat?searchtype=author&query=F%C3%B6hlisch%2C+A">Alexander F枚hlisch</a>, <a href="/search/cond-mat?searchtype=author&query=Gelisio%2C+L">Luca Gelisio</a>, <a href="/search/cond-mat?searchtype=author&query=Gensch%2C+M">Michael Gensch</a>, <a href="/search/cond-mat?searchtype=author&query=Gerasimova%2C+N">Natalia Gerasimova</a> , et al. (39 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2211.04265v3-abstract-short" style="display: inline;"> Femtosecond transient soft X-ray Absorption Spectroscopy (XAS) is a very promising technique that can be employed at X-ray Free Electron Lasers (FELs) to investigate out-of-equilibrium dynamics for material and energy research. Here we present a dedicated setup for soft X-rays available at the Spectroscopy & Coherent Scattering (SCS) instrument at the European X-ray Free Electron Laser (EuXFEL). I… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.04265v3-abstract-full').style.display = 'inline'; document.getElementById('2211.04265v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2211.04265v3-abstract-full" style="display: none;"> Femtosecond transient soft X-ray Absorption Spectroscopy (XAS) is a very promising technique that can be employed at X-ray Free Electron Lasers (FELs) to investigate out-of-equilibrium dynamics for material and energy research. Here we present a dedicated setup for soft X-rays available at the Spectroscopy & Coherent Scattering (SCS) instrument at the European X-ray Free Electron Laser (EuXFEL). It consists of a beam-splitting off-axis zone plate (BOZ) used in transmission to create three copies of the incoming beam, which are used to measure the transmitted intensity through the excited and unexcited sample, as well as to monitor the incoming intensity. Since these three intensity signals are detected shot-by-shot and simultaneously, this setup allows normalized shot-by-shot analysis of the transmission. For photon detection, the DSSC imaging detector, which is capable of recording up to 800 images at 4.5 MHz frame rate during the FEL burst, is employed and allows approaching the photon shot-noise limit. We review the setup and its capabilities, as well as the online and offline analysis tools provided to users. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.04265v3-abstract-full').style.display = 'none'; document.getElementById('2211.04265v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 January, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 8 November, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">11 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> J. Synchrotron Rad. (2023). 30, 284-300 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2211.03562">arXiv:2211.03562</a> <span> [<a href="https://arxiv.org/pdf/2211.03562">pdf</a>, <a href="https://arxiv.org/format/2211.03562">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> </div> </div> <p class="title is-5 mathjax"> Electronic and structural fingerprints of charge density wave excitations in extreme ultraviolet transient absorption spectroscopy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Heinrich%2C+T">Tobias Heinrich</a>, <a href="/search/cond-mat?searchtype=author&query=Chang%2C+H">Hung-Tzu Chang</a>, <a href="/search/cond-mat?searchtype=author&query=Zayko%2C+S">Sergey Zayko</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Sivis%2C+M">Murat Sivis</a>, <a href="/search/cond-mat?searchtype=author&query=Ropers%2C+C">Claus Ropers</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2211.03562v1-abstract-short" style="display: inline;"> Femtosecond core-level transient absorption spectroscopy is utilized to investigate photoinduced dynamics of the charge density wave in 1T-TiSe2 at the Ti M2,3 edge (30-50 eV). Photoexcited carriers and phonons are found to primarily induce spectral red-shifts of core-level excitations, and a carrier relaxation time and phonon heating time of approximately 360 fs and 1.0 ps are extracted, respecti… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.03562v1-abstract-full').style.display = 'inline'; document.getElementById('2211.03562v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2211.03562v1-abstract-full" style="display: none;"> Femtosecond core-level transient absorption spectroscopy is utilized to investigate photoinduced dynamics of the charge density wave in 1T-TiSe2 at the Ti M2,3 edge (30-50 eV). Photoexcited carriers and phonons are found to primarily induce spectral red-shifts of core-level excitations, and a carrier relaxation time and phonon heating time of approximately 360 fs and 1.0 ps are extracted, respectively. Pronounced oscillations in delay-dependent absorption spectra are assigned to coherent excitations of the optical $A_{1g}$ phonon (6.0 THz) and the $A_{1g}^*$ charge density wave amplitude mode (3.3 THz). By comparing the measured spectra with time-dependent density functional theory simulations, we determine the directions of the momentary atomic displacements of both coherent modes and estimate their amplitudes. This work presents a first look on charge density wave excitations with table-top core-level transient absorption spectroscopy, enabling simultaneous access to electronic and lattice excitation and relaxation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2211.03562v1-abstract-full').style.display = 'none'; document.getElementById('2211.03562v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 7 November, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2210.01693">arXiv:2210.01693</a> <span> [<a href="https://arxiv.org/pdf/2210.01693">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41567-023-01954-3">10.1038/s41567-023-01954-3 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Phase-locked photon-electron interaction without a laser </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Taleb%2C+M">Masoud Taleb</a>, <a href="/search/cond-mat?searchtype=author&query=Hentschel%2C+M">Mario Hentschel</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Giessen%2C+H">Harald Giessen</a>, <a href="/search/cond-mat?searchtype=author&query=Talebi%2C+N">Nahid Talebi</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2210.01693v1-abstract-short" style="display: inline;"> Ultrafast electron-photon spectroscopy in electron microscopes commonly requires ultrafast laser setups. Photoemission from an engineered electron source is used to generate pulsed electrons, interacting with a sample that is excited by the ultrafast laser pulse at a specified time delay. Thus, developing an ultrafast electron microscope demands the exploitation of extrinsic laser excitations and… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.01693v1-abstract-full').style.display = 'inline'; document.getElementById('2210.01693v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2210.01693v1-abstract-full" style="display: none;"> Ultrafast electron-photon spectroscopy in electron microscopes commonly requires ultrafast laser setups. Photoemission from an engineered electron source is used to generate pulsed electrons, interacting with a sample that is excited by the ultrafast laser pulse at a specified time delay. Thus, developing an ultrafast electron microscope demands the exploitation of extrinsic laser excitations and complex synchronization schemes. Here, we present an inverse approach based on cathodoluminescence spectroscopy to introduce internal radiation sources in an electron microscope. Our method is based on a sequential interaction of the electron beam with an electron-driven photon source (EDPHS) and the investigated sample. An electron-driven photon source in an electron microscope generates phase-locked photons that are mutually coherent with the near-field distribution of the swift electron. Due to their different velocities, one can readily change the delay between the photons and electrons arriving at the sample by changing the distance between the EDPHS and the sample. We demonstrate the mutual coherence between the radiations from the EDPHS and the sample by performing interferometry with a combined system of an EDPHS and a WSe2 flake. We assert the mutual frequency and momentum-dependent correlation of the EDPHS and sample radiation, and determine experimentally the degree of mutual coherence of up to 27%. This level of mutual coherence allows us to perform spectral interferometry with an electron microscope. Our method has the advantage of being simple, compact and operating with continuous electron beams. It will open the door to local electron-photon correlation spectroscopy of quantum materials, single photon systems, and coherent exciton-polaritonic samples with nanometric resolution. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.01693v1-abstract-full').style.display = 'none'; document.getElementById('2210.01693v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 4 October, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2207.11298">arXiv:2207.11298</a> <span> [<a href="https://arxiv.org/pdf/2207.11298">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Superconductivity">cond-mat.supr-con</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41467-023-43094-5">10.1038/s41467-023-43094-5 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Precursor phase with full phonon softening above the charge-density-wave phase transition in $2H$-TaSe$_2$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Shen%2C+X">Xingchen Shen</a>, <a href="/search/cond-mat?searchtype=author&query=Heid%2C+R">Rolf Heid</a>, <a href="/search/cond-mat?searchtype=author&query=Hott%2C+R">Roland Hott</a>, <a href="/search/cond-mat?searchtype=author&query=Salzmann%2C+B">Bj枚rn Salzmann</a>, <a href="/search/cond-mat?searchtype=author&query=Cantarino%2C+M+d+R">Marli dos Reis Cantarino</a>, <a href="/search/cond-mat?searchtype=author&query=Monney%2C+C">Claude Monney</a>, <a href="/search/cond-mat?searchtype=author&query=Said%2C+A+H">Ayman H. Said</a>, <a href="/search/cond-mat?searchtype=author&query=Murphy%2C+B">Bridget Murphy</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Rosenkranz%2C+S">Stephan Rosenkranz</a>, <a href="/search/cond-mat?searchtype=author&query=Weber%2C+F">Frank Weber</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2207.11298v1-abstract-short" style="display: inline;"> Research on charge-density-wave (CDW) ordered transition-metal dichalcogenides continues to unravel new states of quantum matter correlated to the intertwined lattice and electronic degrees of freedom. Here, we report an inelastic x-ray scattering investigation of the lattice dynamics of the canonical CDW compound $2H$-TaSe$_2$ complemented by angle-resolved photoemission spectroscopy. Our results… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.11298v1-abstract-full').style.display = 'inline'; document.getElementById('2207.11298v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2207.11298v1-abstract-full" style="display: none;"> Research on charge-density-wave (CDW) ordered transition-metal dichalcogenides continues to unravel new states of quantum matter correlated to the intertwined lattice and electronic degrees of freedom. Here, we report an inelastic x-ray scattering investigation of the lattice dynamics of the canonical CDW compound $2H$-TaSe$_2$ complemented by angle-resolved photoemission spectroscopy. Our results rule out the central-peak scenario for the CDW transition in $2H$-TaSe$_2$ and provide evidence for a novel precursor phase above the CDW transition temperature $T_{CDW}$. The phase at temperatures between $T^{*}\,(= 128.7\,,\rm{K})$ and $T_{CDW}\,(= 121.3\,\rm{K})$ is characterized by a fully softened phonon mode and medium-range ordered ($尉_{corr} = 100\,\rm{\mathring{A}}- 200\,\rm{\mathring{A}})$ static CDW domains. Only $T_{CDW}$ is detectable in our photoemission experiments. Thus, $2H$-TaSe$_2$ exhibits structural before electronic static order and emphasizes the important lattice contribution to CDW transitions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.11298v1-abstract-full').style.display = 'none'; document.getElementById('2207.11298v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 July, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Nature Communications 2023 Vol. 14 Issue 1 Pages 7282 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2207.05571">arXiv:2207.05571</a> <span> [<a href="https://arxiv.org/pdf/2207.05571">pdf</a>, <a href="https://arxiv.org/format/2207.05571">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41563-023-01600-6">10.1038/s41563-023-01600-6 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Light-induced hexatic state in a layered quantum material </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Domr%C3%B6se%2C+T">Till Domr枚se</a>, <a href="/search/cond-mat?searchtype=author&query=Danz%2C+T">Thomas Danz</a>, <a href="/search/cond-mat?searchtype=author&query=Schaible%2C+S+F">Sophie F. Schaible</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Yalunin%2C+S+V">Sergey V. Yalunin</a>, <a href="/search/cond-mat?searchtype=author&query=Ropers%2C+C">Claus Ropers</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2207.05571v2-abstract-short" style="display: inline;"> The tunability of materials properties by light promises a wealth of future applications in energy conversion and information technology. Strongly correlated materials such as transition-metal dichalcogenides (TMDCs) offer optical control of electronic phases, charge ordering and interlayer correlations by photodoping. Here, we find the emergence of a transient hexatic state in a TMDC thin-film du… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.05571v2-abstract-full').style.display = 'inline'; document.getElementById('2207.05571v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2207.05571v2-abstract-full" style="display: none;"> The tunability of materials properties by light promises a wealth of future applications in energy conversion and information technology. Strongly correlated materials such as transition-metal dichalcogenides (TMDCs) offer optical control of electronic phases, charge ordering and interlayer correlations by photodoping. Here, we find the emergence of a transient hexatic state in a TMDC thin-film during the laser-induced transformation between two charge-density wave (CDW) phases. Introducing tilt-series ultrafast nanobeam electron diffraction, we reconstruct CDW rocking curves at high momentum resolution. An intermittent suppression of three-dimensional structural correlations promotes a loss of in-plane translational order characteristic of a hexatic intermediate. Our results demonstrate the merit of tomographic ultrafast structural probing in tracing coupled order parameters, heralding universal nanoscale access to laser-induced dimensionality control in functional heterostructures and devices. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2207.05571v2-abstract-full').style.display = 'none'; document.getElementById('2207.05571v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 July, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 12 July, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2203.15560">arXiv:2203.15560</a> <span> [<a href="https://arxiv.org/pdf/2203.15560">pdf</a>, <a href="https://arxiv.org/format/2203.15560">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41535-022-00508-9">10.1038/s41535-022-00508-9 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Orbital-selective Band Hybridisation at the Charge Density Wave Transition in Monolayer TiTe$_2$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Antonelli%2C+T">T. Antonelli</a>, <a href="/search/cond-mat?searchtype=author&query=Rahim%2C+W">W. Rahim</a>, <a href="/search/cond-mat?searchtype=author&query=Watson%2C+M+D">M. D. Watson</a>, <a href="/search/cond-mat?searchtype=author&query=Rajan%2C+A">A. Rajan</a>, <a href="/search/cond-mat?searchtype=author&query=Clark%2C+O+J">O. J. Clark</a>, <a href="/search/cond-mat?searchtype=author&query=Danilenko%2C+A">A. Danilenko</a>, <a href="/search/cond-mat?searchtype=author&query=Underwood%2C+K">K. Underwood</a>, <a href="/search/cond-mat?searchtype=author&query=Markovic%2C+I">I. Markovic</a>, <a href="/search/cond-mat?searchtype=author&query=Abarca-Morales%2C+E">E. Abarca-Morales</a>, <a href="/search/cond-mat?searchtype=author&query=Kavanagh%2C+S+R">S. R. Kavanagh</a>, <a href="/search/cond-mat?searchtype=author&query=Fevre%2C+P">P. Fevre</a>, <a href="/search/cond-mat?searchtype=author&query=Bertran%2C+F">F. Bertran</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">K. Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Scanlon%2C+D+O">D. O. Scanlon</a>, <a href="/search/cond-mat?searchtype=author&query=King%2C+P+D+C">P. D. C. King</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2203.15560v1-abstract-short" style="display: inline;"> An anomalous $(2\times2)$ charge density wave (CDW) phase emerges in monolayer 1T-TiTe$_2$ which is absent for the bulk compound, and whose origin is still poorly understood. Here, we investigate the electronic band structure evolution across the CDW transition using temperature-dependent angle-resolved photoemission spectroscopy. Our study reveals an orbital-selective band hybridisation between t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.15560v1-abstract-full').style.display = 'inline'; document.getElementById('2203.15560v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2203.15560v1-abstract-full" style="display: none;"> An anomalous $(2\times2)$ charge density wave (CDW) phase emerges in monolayer 1T-TiTe$_2$ which is absent for the bulk compound, and whose origin is still poorly understood. Here, we investigate the electronic band structure evolution across the CDW transition using temperature-dependent angle-resolved photoemission spectroscopy. Our study reveals an orbital-selective band hybridisation between the backfolded conduction and valence bands occurring at the CDW phase transition, which in turn leads to a significant electronic energy gain, underpinning the CDW transition. For the bulk compound, we show how this energy gain is almost completely suppressed due to the three-dimensionality of the electronic band structure, including via a $k_z$-dependent band inversion which switches the orbital character of the valence states. Our study thus sheds new light on how control of the electronic dimensionalilty can be used to trigger the emergence of new collective states in 2D materials. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.15560v1-abstract-full').style.display = 'none'; document.getElementById('2203.15560v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 29 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> npj Quantum Mater. 7, 98 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2203.11121">arXiv:2203.11121</a> <span> [<a href="https://arxiv.org/pdf/2203.11121">pdf</a>, <a href="https://arxiv.org/format/2203.11121">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Instrumentation and Detectors">physics.ins-det</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1063/5.0091003">10.1063/5.0091003 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Multispectral time-resolved energy-momentum microscopy using high-harmonic extreme ultraviolet radiation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Heber%2C+M">Michael Heber</a>, <a href="/search/cond-mat?searchtype=author&query=Wind%2C+N">Nils Wind</a>, <a href="/search/cond-mat?searchtype=author&query=Kutnyakhov%2C+D">Dmytro Kutnyakhov</a>, <a href="/search/cond-mat?searchtype=author&query=Pressacco%2C+F">Federico Pressacco</a>, <a href="/search/cond-mat?searchtype=author&query=Arion%2C+T">Tiberiu Arion</a>, <a href="/search/cond-mat?searchtype=author&query=Roth%2C+F">Friedrich Roth</a>, <a href="/search/cond-mat?searchtype=author&query=Eberhardt%2C+W">Wolfgang Eberhardt</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2203.11121v2-abstract-short" style="display: inline;"> A 790-nm-driven high-harmonic generation source with a repetition rate of 6 kHz is combined with a toroidal-grating monochromator and a high-detection-efficiency photoelectron time-of-flight momentum microscope to enable time- and momentum-resolved photoemission spectroscopy over a spectral range of $23.6$-$45.5$ eV with sub-100-fs time resolution. Three-dimensional (3D) Fermi surface mapping is d… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.11121v2-abstract-full').style.display = 'inline'; document.getElementById('2203.11121v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2203.11121v2-abstract-full" style="display: none;"> A 790-nm-driven high-harmonic generation source with a repetition rate of 6 kHz is combined with a toroidal-grating monochromator and a high-detection-efficiency photoelectron time-of-flight momentum microscope to enable time- and momentum-resolved photoemission spectroscopy over a spectral range of $23.6$-$45.5$ eV with sub-100-fs time resolution. Three-dimensional (3D) Fermi surface mapping is demonstrated on graphene-covered Ir(111) with energy and momentum resolutions of $\lesssim$$100$ meV and $\lesssim$$0.1$ $脜^{-1}$, respectively. The table-top experiment sets the stage for measuring the $k_z$-dependent ultrafast dynamics of 3D electronic structure, including band structure, Fermi surface, and carrier dynamics in 3D materials as well as 3D orbital dynamics in molecular layers. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.11121v2-abstract-full').style.display = 'none'; document.getElementById('2203.11121v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 July, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 21 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Review of Scientific Instruments 93, 083905 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2203.05655">arXiv:2203.05655</a> <span> [<a href="https://arxiv.org/pdf/2203.05655">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1021/acs.nanolett.3c01078">10.1021/acs.nanolett.3c01078 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Bipolaronic nature of the pseudogap in (TaSe4)2I revealed via weak photoexcitation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Zhang%2C+Y">Yingchao Zhang</a>, <a href="/search/cond-mat?searchtype=author&query=Kafle%2C+T">Tika Kafle</a>, <a href="/search/cond-mat?searchtype=author&query=You%2C+W">Wenjing You</a>, <a href="/search/cond-mat?searchtype=author&query=Shi%2C+X">Xun Shi</a>, <a href="/search/cond-mat?searchtype=author&query=Min%2C+L">Lujin Min</a>, <a href="/search/cond-mat?searchtype=author&query=Huaiyu"> Huaiyu</a>, <a href="/search/cond-mat?searchtype=author&query=Wang"> Wang</a>, <a href="/search/cond-mat?searchtype=author&query=Li%2C+N">Na Li</a>, <a href="/search/cond-mat?searchtype=author&query=Gopalan%2C+V">Venkatraman Gopalan</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Yang%2C+L">Lexian Yang</a>, <a href="/search/cond-mat?searchtype=author&query=Mao%2C+Z">Zhiqiang Mao</a>, <a href="/search/cond-mat?searchtype=author&query=Nandkishore%2C+R">Rahul Nandkishore</a>, <a href="/search/cond-mat?searchtype=author&query=Kapteyn%2C+H">Henry Kapteyn</a>, <a href="/search/cond-mat?searchtype=author&query=Murnane%2C+M">Margaret Murnane</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2203.05655v1-abstract-short" style="display: inline;"> The origin of the pseudogap in many strongly correlated materials has been a longstanding puzzle. Here, we uncover which many-body interactions underlie the pseudogap in quasi-one-dimensional (quasi-1D) material (TaSe4)2I by weak photo-excitation of the material to partially melt the ground state order and thereby reveal the underlying states in the gap. We observe the appearance of both dispersiv… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.05655v1-abstract-full').style.display = 'inline'; document.getElementById('2203.05655v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2203.05655v1-abstract-full" style="display: none;"> The origin of the pseudogap in many strongly correlated materials has been a longstanding puzzle. Here, we uncover which many-body interactions underlie the pseudogap in quasi-one-dimensional (quasi-1D) material (TaSe4)2I by weak photo-excitation of the material to partially melt the ground state order and thereby reveal the underlying states in the gap. We observe the appearance of both dispersive and flat bands by using time- and angle-resolved photoemission spectroscopy. We assign the dispersive band to a single-particle bare band, while the flat band to a collection of single-polaron sub-bands. Our results provide direct experimental evidence that many-body interactions among small Holstein polarons i.e., the formation of bipolarons, are primarily responsible for the pseudogap in (TaSe4)2I. Recent theoretical studies of the Holstein model support the presence of such a bipolaron-to-polaron crossover. We also observe dramatically different relaxation times for the excited in-gap states in (TaSe4)2I (~600 fs) compared with another quasi-1D material Rb0.3MoO3 (~60 fs), which provides a new method for distinguishing between pseudogaps induced by polaronic or Luttinger-liquid many-body interactions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.05655v1-abstract-full').style.display = 'none'; document.getElementById('2203.05655v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 10 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2022. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Nano Lett 2023, 23, 18, 8392-8398 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2201.10194">arXiv:2201.10194</a> <span> [<a href="https://arxiv.org/pdf/2201.10194">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> </div> </div> <p class="title is-5 mathjax"> Tailoring the band structure of plexcitonic crystals by strong coupling </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Davoodi%2C+F">Fatemeh Davoodi</a>, <a href="/search/cond-mat?searchtype=author&query=Taleb%2C+M">Masoud Taleb</a>, <a href="/search/cond-mat?searchtype=author&query=Diekmann%2C+F+K">Florian K. Diekmann</a>, <a href="/search/cond-mat?searchtype=author&query=Coenen%2C+T">Toon Coenen</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Talebi%2C+N">Nahid Talebi</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2201.10194v1-abstract-short" style="display: inline;"> Transition-metal dichalcogenides with their exciton-dominated optical behavior emerge as promising materials for realizing strong light-matter interactions in the visible range and at ambient conditions. When these materials are combined with metals, the energy confining ability of plasmon polaritons in metals below the diffraction limit, allows for further enhancing and tailoring the light-matter… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2201.10194v1-abstract-full').style.display = 'inline'; document.getElementById('2201.10194v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2201.10194v1-abstract-full" style="display: none;"> Transition-metal dichalcogenides with their exciton-dominated optical behavior emerge as promising materials for realizing strong light-matter interactions in the visible range and at ambient conditions. When these materials are combined with metals, the energy confining ability of plasmon polaritons in metals below the diffraction limit, allows for further enhancing and tailoring the light-matter interaction, due to the formation of plexcitons in hybrid metal-TMDC structures at the interface. Herein, we demonstrate that the coupling between quasi-propagating plasmons in plasmonic crystals and excitons in WSe2, provides a multi-oscillator playground for tailoring the band structure of plasmonic crystal structures and results in emerging flat bands. The cathodoluminescence spectroscopy and angle-resolved measurements combined with the numerically calculated photonic band structure confirm a strong exciton-plasmon coupling, leading to significant changes in the band diagram of the hybrid lattice and the ability to tailor the band diagram via strong coupling. The hybrid plexcitonic crystal structures investigated here sustain optical waves with remarkably low group velocities. These results could be used for designing tunable slow-light structures based on the strong-coupling effect and pave the way toward plexcitonic topological photonic structures. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2201.10194v1-abstract-full').style.display = 'none'; document.getElementById('2201.10194v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 January, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2107.06361">arXiv:2107.06361</a> <span> [<a href="https://arxiv.org/pdf/2107.06361">pdf</a>, <a href="https://arxiv.org/format/2107.06361">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Superconductivity">cond-mat.supr-con</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41467-022-29879-0">10.1038/s41467-022-29879-0 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Quantum spins and hybridization in artificially-constructed chains of magnetic adatoms on a superconductor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Liebhaber%2C+E">Eva Liebhaber</a>, <a href="/search/cond-mat?searchtype=author&query=R%C3%BCtten%2C+L+M">Lisa M. R眉tten</a>, <a href="/search/cond-mat?searchtype=author&query=Reecht%2C+G">Ga毛l Reecht</a>, <a href="/search/cond-mat?searchtype=author&query=Steiner%2C+J+F">Jacob F. Steiner</a>, <a href="/search/cond-mat?searchtype=author&query=Rohlf%2C+S">Sebastian Rohlf</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=von+Oppen%2C+F">Felix von Oppen</a>, <a href="/search/cond-mat?searchtype=author&query=Franke%2C+K+J">Katharina J. Franke</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2107.06361v2-abstract-short" style="display: inline;"> Magnetic adatom chains on surfaces constitute fascinating quantum spin systems. Superconducting substrates suppress interactions with bulk electronic excitations but couple the adatom spins to a chain of subgap Yu-Shiba-Rusinov (YSR) quasiparticles. Using a scanning tunneling microscope, we investigate such correlated spin-fermion systems by constructing Fe chains adatom by adatom on superconducti… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.06361v2-abstract-full').style.display = 'inline'; document.getElementById('2107.06361v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2107.06361v2-abstract-full" style="display: none;"> Magnetic adatom chains on surfaces constitute fascinating quantum spin systems. Superconducting substrates suppress interactions with bulk electronic excitations but couple the adatom spins to a chain of subgap Yu-Shiba-Rusinov (YSR) quasiparticles. Using a scanning tunneling microscope, we investigate such correlated spin-fermion systems by constructing Fe chains adatom by adatom on superconducting NbSe$_2$. The adatoms couple entirely via the substrate, retaining their quantum spin nature. In dimers, we observe that the deepest YSR state undergoes a quantum phase transition due to Ruderman-Kittel-Kasuya-Yosida interactions, a distinct signature of quantum spins. Chains exhibit coherent hybridization and band formation of the YSR excitations, indicating ferromagnetic coupling. Longer chains develop separate domains due to coexisting charge-density-wave order of NbSe$_2$. Despite the spin-orbit-coupled substrate, we find no signatures of Majoranas, possibly because quantum spins reduce the parameter range for topological superconductivity. We suggest that adatom chains are versatile systems for investigating correlated-electron physics and its interplay with topological superconductivity. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2107.06361v2-abstract-full').style.display = 'none'; document.getElementById('2107.06361v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 18 April, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 13 July, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2021. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2105.10472">arXiv:2105.10472</a> <span> [<a href="https://arxiv.org/pdf/2105.10472">pdf</a>, <a href="https://arxiv.org/format/2105.10472">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevB.104.L161104">10.1103/PhysRevB.104.L161104 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Ultrafast electronic line width broadening in the C 1s core level of graphene </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Curcio%2C+D">Davide Curcio</a>, <a href="/search/cond-mat?searchtype=author&query=Pakdel%2C+S">Sahar Pakdel</a>, <a href="/search/cond-mat?searchtype=author&query=Volckaert%2C+K">Klara Volckaert</a>, <a href="/search/cond-mat?searchtype=author&query=Miwa%2C+J+A">Jill A. Miwa</a>, <a href="/search/cond-mat?searchtype=author&query=Ulstrup%2C+S">S酶ren Ulstrup</a>, <a href="/search/cond-mat?searchtype=author&query=Lanat%C3%A0%2C+N">Nicola Lanat脿</a>, <a href="/search/cond-mat?searchtype=author&query=Bianchi%2C+M">Marco Bianchi</a>, <a href="/search/cond-mat?searchtype=author&query=Kutnyakhov%2C+D">Dmytro Kutnyakhov</a>, <a href="/search/cond-mat?searchtype=author&query=Pressacco%2C+F">Federico Pressacco</a>, <a href="/search/cond-mat?searchtype=author&query=Brenner%2C+G">G眉nter Brenner</a>, <a href="/search/cond-mat?searchtype=author&query=Dziarzhytski%2C+S">Siarhei Dziarzhytski</a>, <a href="/search/cond-mat?searchtype=author&query=Redlin%2C+H">Harald Redlin</a>, <a href="/search/cond-mat?searchtype=author&query=Agustsson%2C+S">Steinn Agustsson</a>, <a href="/search/cond-mat?searchtype=author&query=Medjanik%2C+K">Katerina Medjanik</a>, <a href="/search/cond-mat?searchtype=author&query=Vasilyev%2C+D">Dmitry Vasilyev</a>, <a href="/search/cond-mat?searchtype=author&query=Elmers%2C+H">Hans-Joachim Elmers</a>, <a href="/search/cond-mat?searchtype=author&query=Sch%C3%B6nhense%2C+G">Gerd Sch枚nhense</a>, <a href="/search/cond-mat?searchtype=author&query=Tusche%2C+C">Christian Tusche</a>, <a href="/search/cond-mat?searchtype=author&query=Chen%2C+Y">Ying-Jiun Chen</a>, <a href="/search/cond-mat?searchtype=author&query=Speck%2C+F">Florian Speck</a>, <a href="/search/cond-mat?searchtype=author&query=Seyller%2C+T">Thomas Seyller</a>, <a href="/search/cond-mat?searchtype=author&query=B%C3%BChlmann%2C+K">Kevin B眉hlmann</a>, <a href="/search/cond-mat?searchtype=author&query=Gort%2C+R">Rafael Gort</a>, <a href="/search/cond-mat?searchtype=author&query=Diekmann%2C+F">Florian Diekmann</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a> , et al. (9 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2105.10472v1-abstract-short" style="display: inline;"> Core level binding energies and absorption edges are at the heart of many experimental techniques concerned with element-specific structure, electronic structure, chemical reactivity, elementary excitations and magnetism. X-ray photoemission spectroscopy (XPS) in particular, can provide information about the electronic and vibrational many-body interactions in a solid as these are reflected in the… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.10472v1-abstract-full').style.display = 'inline'; document.getElementById('2105.10472v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.10472v1-abstract-full" style="display: none;"> Core level binding energies and absorption edges are at the heart of many experimental techniques concerned with element-specific structure, electronic structure, chemical reactivity, elementary excitations and magnetism. X-ray photoemission spectroscopy (XPS) in particular, can provide information about the electronic and vibrational many-body interactions in a solid as these are reflected in the detailed energy distribution of the photoelectrons. Ultrafast pump-probe techniques add a new dimension to such studies, introducing the ability to probe a transient state of the many-body system. Here we use a free electron laser to investigate the effect of a transiently excited electron gas on the core level spectrum of graphene, showing that it leads to a large broadening of the C 1s peak. Confirming a decade-old prediction, the broadening is found to be caused by an exchange of energy and momentum between the photoemitted core electron and the hot electron system, rather than by vibrational excitations. This interpretation is supported by a line shape analysis that accounts for the presence of the excited electrons. Fitting the spectra to this model directly yields the electronic temperature of the system, in agreement with electronic temperature values obtained from valence band data. Furthermore, making use of time- and momentum-resolved C 1s spectra, we illustrate how the momentum change of the outgoing core electrons leads to a small but detectable change in the time-resolved photoelectron diffraction pattern and to a nearly complete elimination of the core level binding energy variation associated with the narrow $蟽$-band in the C 1s state. The results demonstrate that the XPS line shape can be used as an element-specific and local probe of the excited electron system and that X-ray photoelectron diffraction investigations remain feasible at very high electronic temperatures. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.10472v1-abstract-full').style.display = 'none'; document.getElementById('2105.10472v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 May, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 pages, 12 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. B 104, 161104 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2102.12798">arXiv:2102.12798</a> <span> [<a href="https://arxiv.org/pdf/2102.12798">pdf</a>, <a href="https://arxiv.org/format/2102.12798">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1021/acs.nanolett.1c00801">10.1021/acs.nanolett.1c00801 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> On the survival of Floquet-Bloch states in the presence of scattering </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Aeschlimann%2C+S">S. Aeschlimann</a>, <a href="/search/cond-mat?searchtype=author&query=Sato%2C+S+A">S. A. Sato</a>, <a href="/search/cond-mat?searchtype=author&query=Krause%2C+R">R. Krause</a>, <a href="/search/cond-mat?searchtype=author&query=Ch%C3%A1vez-Cervantes%2C+M">M. Ch谩vez-Cervantes</a>, <a href="/search/cond-mat?searchtype=author&query=De+Giovannini%2C+U">U. De Giovannini</a>, <a href="/search/cond-mat?searchtype=author&query=H%C3%BCbener%2C+H">H. H眉bener</a>, <a href="/search/cond-mat?searchtype=author&query=Forti%2C+S">S. Forti</a>, <a href="/search/cond-mat?searchtype=author&query=Coletti%2C+C">C. Coletti</a>, <a href="/search/cond-mat?searchtype=author&query=Hanff%2C+K">K. Hanff</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">K. Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Rubio%2C+A">A. Rubio</a>, <a href="/search/cond-mat?searchtype=author&query=Gierz%2C+I">I. Gierz</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2102.12798v1-abstract-short" style="display: inline;"> Floquet theory has spawned many exciting possibilities for electronic structure control with light with enormous potential for future applications. The experimental realization in solids, however, largely remains pending. In particular, the influence of scattering on the formation of Floquet-Bloch states remains poorly understood. Here we combine time- and angle-resolved photoemission spectroscopy… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2102.12798v1-abstract-full').style.display = 'inline'; document.getElementById('2102.12798v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2102.12798v1-abstract-full" style="display: none;"> Floquet theory has spawned many exciting possibilities for electronic structure control with light with enormous potential for future applications. The experimental realization in solids, however, largely remains pending. In particular, the influence of scattering on the formation of Floquet-Bloch states remains poorly understood. Here we combine time- and angle-resolved photoemission spectroscopy with time-dependent density functional theory and a two-level model with relaxation to investigate the survival of Floquet-Bloch states in the presence of scattering. We find that Floquet-Bloch states will be destroyed if scattering -- activated by electronic excitations -- prevents the Bloch electrons from following the driving field coherently. The two-level model also shows that Floquet-Bloch states reappear at high field intensities where energy exchange with the driving field dominates over energy dissipation to the bath. Our results clearly indicate the importance of long scattering times combined with strong driving fields for the successful realization of various Floquet phenomena. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2102.12798v1-abstract-full').style.display = 'none'; document.getElementById('2102.12798v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 February, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">27 pages, 5 figues</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2101.11516">arXiv:2101.11516</a> <span> [<a href="https://arxiv.org/pdf/2101.11516">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> </div> </div> <p class="title is-5 mathjax"> Strong Interaction of Cherenkov Radiation with Excitons in WSe2 Crystals </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Jiang%2C+X">Xuke Jiang</a>, <a href="/search/cond-mat?searchtype=author&query=Taleb%2C+M">Masoud Taleb</a>, <a href="/search/cond-mat?searchtype=author&query=Diekmann%2C+F">Florian Diekmann</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Talebi%2C+N">Nahid Talebi</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2101.11516v1-abstract-short" style="display: inline;"> The optical responses of semiconducting transition metal dichalcogenides are dominated by excitons. Being able to strongly interact with light and other materials excitations, excitons in semiconductors are prototypes for investigating many-particle and strong-field physics, including exciton-exciton, exciton-photon, and exciton-phonon interactions. Strong exciton-photon interactions, in particula… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.11516v1-abstract-full').style.display = 'inline'; document.getElementById('2101.11516v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2101.11516v1-abstract-full" style="display: none;"> The optical responses of semiconducting transition metal dichalcogenides are dominated by excitons. Being able to strongly interact with light and other materials excitations, excitons in semiconductors are prototypes for investigating many-particle and strong-field physics, including exciton-exciton, exciton-photon, and exciton-phonon interactions. Strong exciton-photon interactions, in particular, can lead to the emergence of exciton-polariton hybrid quasiparticles with peculiar characteristics, and a tendency toward macroscopic and spontaneous coherence. Normally, far-field and near-field optical spectroscopy techniques are used to investigate exciton-photon interactions. Here, we demonstrate that the radiation generated by moving electrons in transition metal dichalcogenides, namely Cherenkov radiation, can strongly interact with excitons. We investigate the coherence properties and spectral signatures of exciton-photon interactions in TMDC bulk crystals, using cathodoluminescence spectroscopy. Our findings lay the ground for cathodoluminescence spectroscopy and in particular electron-beam techniques as probes of exciton-polariton spontaneous coherence in semiconductors, beyond the well-known plasmonic investigations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.11516v1-abstract-full').style.display = 'none'; document.getElementById('2101.11516v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 27 January, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2021. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2101.01465">arXiv:2101.01465</a> <span> [<a href="https://arxiv.org/pdf/2101.01465">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> </div> </div> <p class="title is-5 mathjax"> Charting the Exciton-Polariton Landscape in WSe2 Thin Flakes by Cathodoluminescence Spectroscopy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Taleb%2C+M">Masoud Taleb</a>, <a href="/search/cond-mat?searchtype=author&query=Davoodi%2C+F">Fatemeh Davoodi</a>, <a href="/search/cond-mat?searchtype=author&query=Diekmann%2C+F">Florian Diekmann</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Talebi%2C+N">Nahid Talebi</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2101.01465v2-abstract-short" style="display: inline;"> Semiconducting transition-metal dichalcogenides (TMDCs) provide a fascinating discovery platform for strong light-matter interaction effects in the visible spectrum at ambient conditions. While most of the work has focused on hybridizing excitons with resonant photonic modes of external mirrors, cavities, or nanostructures, intriguingly, TMDC flakes of sub-wavelength thickness can themselves act a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.01465v2-abstract-full').style.display = 'inline'; document.getElementById('2101.01465v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2101.01465v2-abstract-full" style="display: none;"> Semiconducting transition-metal dichalcogenides (TMDCs) provide a fascinating discovery platform for strong light-matter interaction effects in the visible spectrum at ambient conditions. While most of the work has focused on hybridizing excitons with resonant photonic modes of external mirrors, cavities, or nanostructures, intriguingly, TMDC flakes of sub-wavelength thickness can themselves act as nanocavities. Here, we determine the optical response of such freestanding planar waveguides of WSe$_2$, by means of cathodoluminescence spectroscopy. We reveal strong exciton-photon interaction effects that foster long-range propagating exciton-polaritons and enable direct imaging of the energy transfer dynamics originating from cavity-like Fabry-Perot resonances. Furthermore, confinement effects due to discontinuities in the flakes are demonstrated as an efficient means to tailor the exciton-photon coupling strength, along the edges of natural flakes. Our combined experimental and theoretical results provide a deeper understanding of exciton-photon self-hybridization in semiconducting TMDCs and may pave the way to optoelectronic nanocircuits exploiting exciton-photon interaction. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2101.01465v2-abstract-full').style.display = 'none'; document.getElementById('2101.01465v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 1 May, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 5 January, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">ACM Class:</span> J.2 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2012.06996">arXiv:2012.06996</a> <span> [<a href="https://arxiv.org/pdf/2012.06996">pdf</a>, <a href="https://arxiv.org/format/2012.06996">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41467-021-23727-3">10.1038/s41467-021-23727-3 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Momentum-space signatures of Berry flux monopoles in a Weyl semimetal </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=%C3%9Cnzelmann%2C+M">M. 脺nzelmann</a>, <a href="/search/cond-mat?searchtype=author&query=Bentmann%2C+H">H. Bentmann</a>, <a href="/search/cond-mat?searchtype=author&query=Figgemeier%2C+T">T. Figgemeier</a>, <a href="/search/cond-mat?searchtype=author&query=Eck%2C+P">P. Eck</a>, <a href="/search/cond-mat?searchtype=author&query=Neu%2C+J+N">J. N. Neu</a>, <a href="/search/cond-mat?searchtype=author&query=Geldiyev%2C+B">B. Geldiyev</a>, <a href="/search/cond-mat?searchtype=author&query=Diekmann%2C+F">F. Diekmann</a>, <a href="/search/cond-mat?searchtype=author&query=Rohlf%2C+S">S. Rohlf</a>, <a href="/search/cond-mat?searchtype=author&query=Buck%2C+J">J. Buck</a>, <a href="/search/cond-mat?searchtype=author&query=Hoesch%2C+M">M. Hoesch</a>, <a href="/search/cond-mat?searchtype=author&query=Kall%C3%A4ne%2C+M">M. Kall盲ne</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">K. Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Thomale%2C+R">R. Thomale</a>, <a href="/search/cond-mat?searchtype=author&query=Siegrist%2C+T">T. Siegrist</a>, <a href="/search/cond-mat?searchtype=author&query=Sangiovanni%2C+G">G. Sangiovanni</a>, <a href="/search/cond-mat?searchtype=author&query=Di+Sante%2C+D">D. Di Sante</a>, <a href="/search/cond-mat?searchtype=author&query=Reinert%2C+F">F. Reinert</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2012.06996v2-abstract-short" style="display: inline;"> Since the early days of Dirac flux quantization, magnetic monopoles have been sought after as a potential corollary of quantized electric charge. As opposed to magnetic monopoles embedded into the theory of electromagnetism, Weyl crystals exhibit Berry flux monopoles in reciprocal parameter space. As a function of crystal momentum, such monopoles locate at the degeneracy point of the Weyl cone. He… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.06996v2-abstract-full').style.display = 'inline'; document.getElementById('2012.06996v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2012.06996v2-abstract-full" style="display: none;"> Since the early days of Dirac flux quantization, magnetic monopoles have been sought after as a potential corollary of quantized electric charge. As opposed to magnetic monopoles embedded into the theory of electromagnetism, Weyl crystals exhibit Berry flux monopoles in reciprocal parameter space. As a function of crystal momentum, such monopoles locate at the degeneracy point of the Weyl cone. Here, we report momentum-resolved spectroscopic signatures of Berry flux monopoles in TaAs as a paradigmatic Weyl semimetal. We have probed the orbital and spin angular momentum (OAM and SAM) of the Weyl-fermion states by angle-resolved photoemission spectroscopy at bulk-sensitive soft X-ray energies (SX-ARPES) combined with photoelectron spin detection and circular dichroism. Supported by first-principles calculations, our measurements image characteristics of a topologically non-trivial winding of the OAM at the Weyl nodes and unveil a chirality-dependent SAM of the Weyl bands. Our results experimentally visualize the non-trivial momentum-space topology in a Weyl semimetal, promising to have profound implications for the study of quantum-geometric effects in solids. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2012.06996v2-abstract-full').style.display = 'none'; document.getElementById('2012.06996v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 21 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 13 December, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2020. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2011.07623">arXiv:2011.07623</a> <span> [<a href="https://arxiv.org/pdf/2011.07623">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1063/4.0000132">10.1063/4.0000132 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Creation of a novel inverted charge density wave state </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Zhang%2C+Y">Yingchao Zhang</a>, <a href="/search/cond-mat?searchtype=author&query=Shi%2C+X">Xun Shi</a>, <a href="/search/cond-mat?searchtype=author&query=Guan%2C+M">Mengxue Guan</a>, <a href="/search/cond-mat?searchtype=author&query=You%2C+W">Wenjing You</a>, <a href="/search/cond-mat?searchtype=author&query=Zhong%2C+Y">Yigui Zhong</a>, <a href="/search/cond-mat?searchtype=author&query=Kafle%2C+T+R">Tika R. Kafle</a>, <a href="/search/cond-mat?searchtype=author&query=Huang%2C+Y">Yaobo Huang</a>, <a href="/search/cond-mat?searchtype=author&query=Ding%2C+H">Hong Ding</a>, <a href="/search/cond-mat?searchtype=author&query=Bauer%2C+M">Michael Bauer</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Meng%2C+S">Sheng Meng</a>, <a href="/search/cond-mat?searchtype=author&query=Kapteyn%2C+H+C">Henry C. Kapteyn</a>, <a href="/search/cond-mat?searchtype=author&query=Murnane%2C+M+M">Margaret M. Murnane</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2011.07623v2-abstract-short" style="display: inline;"> Charge density wave (CDW) order is an emergent quantum phase that is characterized by a periodic lattice distortion and charge density modulation, often present near superconducting transitions. Here we uncover a novel inverted CDW state by using a femtosecond laser to coherently over-drive the unique star-of-David lattice distortion in 1T-TaSe$_2$. We track the signature of this novel CDW state u… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2011.07623v2-abstract-full').style.display = 'inline'; document.getElementById('2011.07623v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2011.07623v2-abstract-full" style="display: none;"> Charge density wave (CDW) order is an emergent quantum phase that is characterized by a periodic lattice distortion and charge density modulation, often present near superconducting transitions. Here we uncover a novel inverted CDW state by using a femtosecond laser to coherently over-drive the unique star-of-David lattice distortion in 1T-TaSe$_2$. We track the signature of this novel CDW state using time- and angle-resolved photoemission spectroscopy and time-dependent density functional theory, and validate that it is associated with a unique lattice and charge arrangement never before realized. The dynamic electronic structure further reveals its novel properties, that are characterized by an increased density of states near the Fermi level, high metallicity, and altered electron-phonon couplings. Our results demonstrate how ultrafast lasers can be used to create unique states in materials, by manipulating charge-lattice orders and couplings. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2011.07623v2-abstract-full').style.display = 'none'; document.getElementById('2011.07623v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 November, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 15 November, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">13 pages, 5 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Structural Dynamics 9, 014501 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2008.11472">arXiv:2008.11472</a> <span> [<a href="https://arxiv.org/pdf/2008.11472">pdf</a>, <a href="https://arxiv.org/format/2008.11472">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevB.100.155407">10.1103/PhysRevB.100.155407 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Surface structure and stacking of the commensurate $\left(\sqrt{13}\times\sqrt{13}\right)$R13.9掳 charge density wave phase of 1T-TaS$_2$(0001) </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=von+Witte%2C+G">Gevin von Witte</a>, <a href="/search/cond-mat?searchtype=author&query=Ki%C3%9Flinger%2C+T">Tilman Ki脽linger</a>, <a href="/search/cond-mat?searchtype=author&query=Horstmann%2C+J+G">Jan Gerrit Horstmann</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Schneider%2C+M+A">M. Alexander Schneider</a>, <a href="/search/cond-mat?searchtype=author&query=Ropers%2C+C">Claus Ropers</a>, <a href="/search/cond-mat?searchtype=author&query=Hammer%2C+L">Lutz Hammer</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2008.11472v1-abstract-short" style="display: inline;"> By quantitative low-energy electron diffraction (LEED) we investigate the extensively studied commensurate charge density wave (CDW) phase of trigonal tantalum disulphide (1T-TaS$_2$), which develops at low temperatures with a $\left(\sqrt{13}\times\sqrt{13}\right)$R13.9掳 periodicity. A full-dynamical analysis of the energy dependence of diffraction spot intensities reveals the entire crystallogra… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2008.11472v1-abstract-full').style.display = 'inline'; document.getElementById('2008.11472v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2008.11472v1-abstract-full" style="display: none;"> By quantitative low-energy electron diffraction (LEED) we investigate the extensively studied commensurate charge density wave (CDW) phase of trigonal tantalum disulphide (1T-TaS$_2$), which develops at low temperatures with a $\left(\sqrt{13}\times\sqrt{13}\right)$R13.9掳 periodicity. A full-dynamical analysis of the energy dependence of diffraction spot intensities reveals the entire crystallographic surface structure, i.e. the detailed atomic positions within the outermost two trilayers consisting of 78 atoms as well as the CDW stacking. The analysis is based on an unusually large data set consisting of spectra for 128 inequivalent beams taken in the energy range 20-250 eV and an excellent fit quality expressed by a bestfit Pendry R-factor of R=0.110. The LEED intensity analysis reveals that the well-accepted model of star-of-David-shaped clusters of Ta atoms for the bulk structure also holds for the outermost two TaS$_2$ trilayers. Specifically, in both layers the clusters of Ta atoms contract laterally by up to 0.25 $脜$ and also slightly rotate within the superstructure cell, causing respective distortions as well as heavy bucklings (up to 0.23 $脜$) in the adjacent sulphur layers. Most importantly, our analysis finds that the CDWs of the 1$^{\text{st}}$ and 2$^{\text{nd}}$ trilayer are vertically aligned, while there is a lateral shift of two units of the basic hexagonal lattice (6.71 $脜$) between the 2$^{\text{nd}}$ and 3$^{\text{rd}}$ trilayer. The results may contribute to a better understanding of the intricate electronic structure of the reference compound 1T-TaS$_2$ and guide the way to the analysis of complex structures in similar quantum materials. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2008.11472v1-abstract-full').style.display = 'none'; document.getElementById('2008.11472v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 August, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">18 pages, 13 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. B 100, 155407 (2019) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2007.08413">arXiv:2007.08413</a> <span> [<a href="https://arxiv.org/pdf/2007.08413">pdf</a>, <a href="https://arxiv.org/format/2007.08413">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41467-020-20829-2">10.1038/s41467-020-20829-2 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Phonon collapse and van der Waals melting of the 3D charge density wave of VSe$_2$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Diego%2C+J">Josu Diego</a>, <a href="/search/cond-mat?searchtype=author&query=Said%2C+A+H">A. H. Said</a>, <a href="/search/cond-mat?searchtype=author&query=Mahatha%2C+S+K">S. K. Mahatha</a>, <a href="/search/cond-mat?searchtype=author&query=Bianco%2C+R">Raffaello Bianco</a>, <a href="/search/cond-mat?searchtype=author&query=Monacelli%2C+L">Lorenzo Monacelli</a>, <a href="/search/cond-mat?searchtype=author&query=Calandra%2C+M">Matteo Calandra</a>, <a href="/search/cond-mat?searchtype=author&query=Mauri%2C+F">Francesco Mauri</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">K. Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Errea%2C+I">Ion Errea</a>, <a href="/search/cond-mat?searchtype=author&query=Blanco-Canosa%2C+S">S. Blanco-Canosa</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2007.08413v1-abstract-short" style="display: inline;"> Among transition metal dichalcogenides (TMDs), VSe$_2$ is considered to develop a purely 3-dimensional (3D) charge-density wave (CDW) at T$_{CDW}$=110 K. Here, by means of high resolution inelastic x-ray scattering (IXS), we show that the CDW transition is driven by the collapse of an acoustic mode at the critical wavevector \textit{q}$_{CDW}$= (2.25 0 0.7) r.l.u. and critical temperature T… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2007.08413v1-abstract-full').style.display = 'inline'; document.getElementById('2007.08413v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2007.08413v1-abstract-full" style="display: none;"> Among transition metal dichalcogenides (TMDs), VSe$_2$ is considered to develop a purely 3-dimensional (3D) charge-density wave (CDW) at T$_{CDW}$=110 K. Here, by means of high resolution inelastic x-ray scattering (IXS), we show that the CDW transition is driven by the collapse of an acoustic mode at the critical wavevector \textit{q}$_{CDW}$= (2.25 0 0.7) r.l.u. and critical temperature T$_{CDW}$=110 K. The softening of this mode starts to be pronounced for temperatures below 2$\times$ T$_{CDW}$ and expands over a rather wide region of the Brillouin zone, suggesting a large contribution of the electron-phonon interaction to the CDW formation. This interpretation is supported by our first principles calculations that determine a large momentum-dependence of the electron-phonon interaction, peaking at the CDW wavevector, in the presence of nesting. Fully anharmonic {\it ab initio} calculations confirm the softening of one acoustic branch at \textit{q}$_{CDW}$ as responsible for the CDW formation and show that van der Waals interactions are crucial to melt the CDW. Our work also highlights the important role of out-of-plane interactions to describe 3D CDWs in TMDs. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2007.08413v1-abstract-full').style.display = 'none'; document.getElementById('2007.08413v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 16 July, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Nat Commun 12, 598 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2006.13702">arXiv:2006.13702</a> <span> [<a href="https://arxiv.org/pdf/2006.13702">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevResearch.3.013128">10.1103/PhysRevResearch.3.013128 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Structurally assisted melting of excitonic correlations in 1T-TiSe2 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Burian%2C+M">Max Burian</a>, <a href="/search/cond-mat?searchtype=author&query=Porer%2C+M">Michael Porer</a>, <a href="/search/cond-mat?searchtype=author&query=Mardegan%2C+J+R+L">Jose R. L. Mardegan</a>, <a href="/search/cond-mat?searchtype=author&query=Esposito%2C+V">Vincent Esposito</a>, <a href="/search/cond-mat?searchtype=author&query=Parchenko%2C+S">Sergii Parchenko</a>, <a href="/search/cond-mat?searchtype=author&query=Burganov%2C+B">Bulat Burganov</a>, <a href="/search/cond-mat?searchtype=author&query=Gurung%2C+N">Namrata Gurung</a>, <a href="/search/cond-mat?searchtype=author&query=Ramakrishnan%2C+M">Mahesh Ramakrishnan</a>, <a href="/search/cond-mat?searchtype=author&query=Scagnoli%2C+V">Valerio Scagnoli</a>, <a href="/search/cond-mat?searchtype=author&query=Ueda%2C+H">Hiroki Ueda</a>, <a href="/search/cond-mat?searchtype=author&query=Francoual%2C+S">Sonia Francoual</a>, <a href="/search/cond-mat?searchtype=author&query=Fabrizi%2C+F">Federica Fabrizi</a>, <a href="/search/cond-mat?searchtype=author&query=Tanaka%2C+Y">Yoshikazu Tanaka</a>, <a href="/search/cond-mat?searchtype=author&query=Togashi%2C+T">Tadashi Togashi</a>, <a href="/search/cond-mat?searchtype=author&query=Kubota%2C+Y">Yuya Kubota</a>, <a href="/search/cond-mat?searchtype=author&query=Yabashi%2C+M">Makina Yabashi</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Johnson%2C+S+L">Steven L. Johnson</a>, <a href="/search/cond-mat?searchtype=author&query=Staub%2C+U">Urs Staub</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2006.13702v1-abstract-short" style="display: inline;"> The simultaneous condensation of electronic and structural degrees of freedom gives rise to new states of matter, including superconductivity and charge-density-wave formation. When exciting such a condensed system, it is commonly assumed that the ultrafast laser pulse disturbs primarily the electronic order, which in turn destabilizes the atomic structure. Contrary to this conception, we show her… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2006.13702v1-abstract-full').style.display = 'inline'; document.getElementById('2006.13702v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2006.13702v1-abstract-full" style="display: none;"> The simultaneous condensation of electronic and structural degrees of freedom gives rise to new states of matter, including superconductivity and charge-density-wave formation. When exciting such a condensed system, it is commonly assumed that the ultrafast laser pulse disturbs primarily the electronic order, which in turn destabilizes the atomic structure. Contrary to this conception, we show here that structural destabilization of few atoms causes melting of the macroscopic ordered charge-density wave in 1T-TiSe2. Using ultrafast pump-probe non-resonant and resonant X-ray diffraction, we observe full suppression of the Se 4p orbital order and the atomic structure at excitation energies more than one order of magnitude below the suggested excitonic binding energy. Complete melting of the charge-density wave occurs 4-5 times faster than expected from a purely electronic charge-screening process, strongly suggesting a structurally assisted breakup of excitonic correlations. Our experimental data clarifies several questions on the intricate coupling between structural and electronic order in stabilizing the charge-density-wave in 1T-TiSe2. The results further show that electron-phonon-coupling can lead to different, energy dependent phase-transition pathways in condensed matter systems, opening new possibilities in the conception of non-equilibrium phenomena at the ultrafast scale. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2006.13702v1-abstract-full').style.display = 'none'; document.getElementById('2006.13702v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 June, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">19 pages, 4 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Research 3, 013128 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2006.13119">arXiv:2006.13119</a> <span> [<a href="https://arxiv.org/pdf/2006.13119">pdf</a>, <a href="https://arxiv.org/format/2006.13119">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Superconductivity">cond-mat.supr-con</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevB.102.245153">10.1103/PhysRevB.102.245153 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Oxide Fermi liquid universality revealed by electron spectroscopy </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Horio%2C+M">M. Horio</a>, <a href="/search/cond-mat?searchtype=author&query=Kramer%2C+K+P">K. P. Kramer</a>, <a href="/search/cond-mat?searchtype=author&query=Wang%2C+Q">Q. Wang</a>, <a href="/search/cond-mat?searchtype=author&query=Zaidan%2C+A">A. Zaidan</a>, <a href="/search/cond-mat?searchtype=author&query=von+Arx%2C+K">K. von Arx</a>, <a href="/search/cond-mat?searchtype=author&query=Sutter%2C+D">D. Sutter</a>, <a href="/search/cond-mat?searchtype=author&query=Matt%2C+C+E">C. E. Matt</a>, <a href="/search/cond-mat?searchtype=author&query=Sassa%2C+Y">Y. Sassa</a>, <a href="/search/cond-mat?searchtype=author&query=Plumb%2C+N+C">N. C. Plumb</a>, <a href="/search/cond-mat?searchtype=author&query=Shi%2C+M">M. Shi</a>, <a href="/search/cond-mat?searchtype=author&query=Hanff%2C+A">A. Hanff</a>, <a href="/search/cond-mat?searchtype=author&query=Mahatha%2C+S+K">S. K. Mahatha</a>, <a href="/search/cond-mat?searchtype=author&query=Bentmann%2C+H">H. Bentmann</a>, <a href="/search/cond-mat?searchtype=author&query=Reinert%2C+F">F. Reinert</a>, <a href="/search/cond-mat?searchtype=author&query=Rohlf%2C+S">S. Rohlf</a>, <a href="/search/cond-mat?searchtype=author&query=Diekmann%2C+F+K">F. K. Diekmann</a>, <a href="/search/cond-mat?searchtype=author&query=Buck%2C+J">J. Buck</a>, <a href="/search/cond-mat?searchtype=author&query=Kall%C3%A4ne%2C+M">M. Kall盲ne</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">K. Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Rienks%2C+E">E. Rienks</a>, <a href="/search/cond-mat?searchtype=author&query=Granata%2C+V">V. Granata</a>, <a href="/search/cond-mat?searchtype=author&query=Fittipaldi%2C+R">R. Fittipaldi</a>, <a href="/search/cond-mat?searchtype=author&query=Vecchione%2C+A">A. Vecchione</a>, <a href="/search/cond-mat?searchtype=author&query=Ohgi%2C+T">T. Ohgi</a>, <a href="/search/cond-mat?searchtype=author&query=Kawamata%2C+T">T. Kawamata</a> , et al. (5 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2006.13119v2-abstract-short" style="display: inline;"> We present a combined soft x-ray and high-resolution vacuum-ultraviolet angle-resolved photoemission spectroscopy study of the electron-overdoped cuprate Pr$_{1.3-x}$La$_{0.7}$Ce$_{x}$CuO$_4$ (PLCCO). Demonstration of its highly two-dimensional band structure enabled precise determination of the in-plane self-energy dominated by electron-electron scattering. Through analysis of this self-energy an… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2006.13119v2-abstract-full').style.display = 'inline'; document.getElementById('2006.13119v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2006.13119v2-abstract-full" style="display: none;"> We present a combined soft x-ray and high-resolution vacuum-ultraviolet angle-resolved photoemission spectroscopy study of the electron-overdoped cuprate Pr$_{1.3-x}$La$_{0.7}$Ce$_{x}$CuO$_4$ (PLCCO). Demonstration of its highly two-dimensional band structure enabled precise determination of the in-plane self-energy dominated by electron-electron scattering. Through analysis of this self-energy and the Fermi-liquid cut-off energy scale, we find -- in contrast to hole-doped cuprates -- a momentum isotropic and comparatively weak electron correlation in PLCCO. Yet, the self-energies extracted from multiple oxide systems combine to demonstrate a logarithmic divergent relation between the quasiparticle scattering rate and mass. This constitutes a spectroscopic version of the Kadowaki-Woods relation with an important merit -- the demonstration of Fermi liquid quasiparticle lifetime and mass being set by a single energy scale. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2006.13119v2-abstract-full').style.display = 'none'; document.getElementById('2006.13119v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 December, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 23 June, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. B 102, 245153 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2006.08983">arXiv:2006.08983</a> <span> [<a href="https://arxiv.org/pdf/2006.08983">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevResearch.3.L022003">10.1103/PhysRevResearch.3.L022003 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Correlation between electronic and structural orders in 1T-TiSe2 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Ueda%2C+H">Hiroki Ueda</a>, <a href="/search/cond-mat?searchtype=author&query=Porer%2C+M">Michael Porer</a>, <a href="/search/cond-mat?searchtype=author&query=Mardegan%2C+J+R+L">Jos茅 R. L. Mardegan</a>, <a href="/search/cond-mat?searchtype=author&query=Parchenko%2C+S">Sergii Parchenko</a>, <a href="/search/cond-mat?searchtype=author&query=Gurung%2C+N">Namrata Gurung</a>, <a href="/search/cond-mat?searchtype=author&query=Fabrizi%2C+F">Federica Fabrizi</a>, <a href="/search/cond-mat?searchtype=author&query=Ramakrishnan%2C+M">Mahesh Ramakrishnan</a>, <a href="/search/cond-mat?searchtype=author&query=Boie%2C+L">Larissa Boie</a>, <a href="/search/cond-mat?searchtype=author&query=Neugebauer%2C+M+J">Martin Josef Neugebauer</a>, <a href="/search/cond-mat?searchtype=author&query=Burganov%2C+B">Bulat Burganov</a>, <a href="/search/cond-mat?searchtype=author&query=Burian%2C+M">Max Burian</a>, <a href="/search/cond-mat?searchtype=author&query=Johnson%2C+S+L">Steven Lee Johnson</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Staub%2C+U">Urs Staub</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2006.08983v1-abstract-short" style="display: inline;"> The correlation between electronic and crystal structures of 1T-TiSe2 in the charge density wave (CDW) state is studied by x-ray diffraction. Three families of reflections are used to probe atomic displacements and the orbital asymmetry in Se. Two distinct onset temperatures are found, TCDW and a lower T* indicative for an onset of Se out-of-plane atomic displacements. T* coincides with a DC resis… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2006.08983v1-abstract-full').style.display = 'inline'; document.getElementById('2006.08983v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2006.08983v1-abstract-full" style="display: none;"> The correlation between electronic and crystal structures of 1T-TiSe2 in the charge density wave (CDW) state is studied by x-ray diffraction. Three families of reflections are used to probe atomic displacements and the orbital asymmetry in Se. Two distinct onset temperatures are found, TCDW and a lower T* indicative for an onset of Se out-of-plane atomic displacements. T* coincides with a DC resistivity maximum and the onset of the proposed gyrotropic electronic structure. However, no indication for chirality is found. The relation between the atomic displacements and the transport properties is discussed in terms of Ti 3d and Se 4p states that only weakly couple to the CDW order. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2006.08983v1-abstract-full').style.display = 'none'; document.getElementById('2006.08983v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 16 June, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">16 pages, 4 figures + 13 pages supplementary info</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Research 3, 022003 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2005.08523">arXiv:2005.08523</a> <span> [<a href="https://arxiv.org/pdf/2005.08523">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.125.266402">10.1103/PhysRevLett.125.266402 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Bypassing the structural bottleneck in the ultrafast melting of electronic order </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Yang%2C+L+X">L. X. Yang</a>, <a href="/search/cond-mat?searchtype=author&query=Rohde%2C+G">G. Rohde</a>, <a href="/search/cond-mat?searchtype=author&query=Stange%2C+K+H+A">K. Hanff. A. Stange</a>, <a href="/search/cond-mat?searchtype=author&query=Xiong%2C+R">R. Xiong</a>, <a href="/search/cond-mat?searchtype=author&query=Shi%2C+J">J. Shi</a>, <a href="/search/cond-mat?searchtype=author&query=Bauer%2C+M">M. Bauer</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">K. Rossnagel</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2005.08523v2-abstract-short" style="display: inline;"> The emergent properties of quantum materials, such as symmetry-broken phases and associated spectral gaps, can be effectively manipulated by ultrashort photon pulses. Impulsive optical excitation generally results in a complex non-equilibrium electron and lattice dynamics that involves multiple processes on distinct timescales, and a common conception is that for times shorter than about 100 fs th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2005.08523v2-abstract-full').style.display = 'inline'; document.getElementById('2005.08523v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2005.08523v2-abstract-full" style="display: none;"> The emergent properties of quantum materials, such as symmetry-broken phases and associated spectral gaps, can be effectively manipulated by ultrashort photon pulses. Impulsive optical excitation generally results in a complex non-equilibrium electron and lattice dynamics that involves multiple processes on distinct timescales, and a common conception is that for times shorter than about 100 fs the gap in the electronic spectrum is not seriously affected by lattice vibrations. Here, we directly monitor the photo-induced collapse of the spectral gap in a canonical charge-density-wave material, blue bronze Rb0.3MoO3. We find that ultra-fast (about 60 fs) vibrational disordering due to efficient hot-electron energy dissipation quenches the gap significantly faster than the typical structural bottleneck time corresponding to one half-cycle oscillation (about 315 fs) of the coherent charge-density-wave amplitude mode. This result not only demonstrates the importance of incoherent lattice motion in the photo-induced quenching of electronic order, but also resolves the perennial debate about the nature of the spectral gap in a coupled electron-lattice system. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2005.08523v2-abstract-full').style.display = 'none'; document.getElementById('2005.08523v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 19 May, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 18 May, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 125, 266402 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2001.05541">arXiv:2001.05541</a> <span> [<a href="https://arxiv.org/pdf/2001.05541">pdf</a>, <a href="https://arxiv.org/ps/2001.05541">ps</a>, <a href="https://arxiv.org/format/2001.05541">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41535-020-00288-0">10.1038/s41535-020-00288-0 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Ubiquitous impact of localised impurity states on the exchange coupling mechanism in magnetic topological insulators </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Peixoto%2C+T+R+F">Thiago R. F. Peixoto</a>, <a href="/search/cond-mat?searchtype=author&query=Bentmann%2C+H">Hendrik Bentmann</a>, <a href="/search/cond-mat?searchtype=author&query=R%C3%BC%C3%9Fmann%2C+P">Philipp R眉脽mann</a>, <a href="/search/cond-mat?searchtype=author&query=Tcakaev%2C+A">Abdul-Vakhab Tcakaev</a>, <a href="/search/cond-mat?searchtype=author&query=Winnerlein%2C+M">Martin Winnerlein</a>, <a href="/search/cond-mat?searchtype=author&query=Schreyeck%2C+S">Steffen Schreyeck</a>, <a href="/search/cond-mat?searchtype=author&query=Schatz%2C+S">Sonja Schatz</a>, <a href="/search/cond-mat?searchtype=author&query=Vidal%2C+R+C">Raphael Crespo Vidal</a>, <a href="/search/cond-mat?searchtype=author&query=Stier%2C+F">Fabian Stier</a>, <a href="/search/cond-mat?searchtype=author&query=Zabolotnyy%2C+V">Volodymyr Zabolotnyy</a>, <a href="/search/cond-mat?searchtype=author&query=Green%2C+R+J">Robert J. Green</a>, <a href="/search/cond-mat?searchtype=author&query=Min%2C+C+H">Chul Hee Min</a>, <a href="/search/cond-mat?searchtype=author&query=Fornari%2C+C+I">Celso I. Fornari</a>, <a href="/search/cond-mat?searchtype=author&query=Maa%C3%9F%2C+H">Henriette Maa脽</a>, <a href="/search/cond-mat?searchtype=author&query=Vasili%2C+H+B">Hari Babu Vasili</a>, <a href="/search/cond-mat?searchtype=author&query=Gargiani%2C+P">Pierluigi Gargiani</a>, <a href="/search/cond-mat?searchtype=author&query=Valvidares%2C+M">Manuel Valvidares</a>, <a href="/search/cond-mat?searchtype=author&query=Barla%2C+A">Alessandro Barla</a>, <a href="/search/cond-mat?searchtype=author&query=Buck%2C+J">Jens Buck</a>, <a href="/search/cond-mat?searchtype=author&query=Hoesch%2C+M">Moritz Hoesch</a>, <a href="/search/cond-mat?searchtype=author&query=Diekmann%2C+F">Florian Diekmann</a>, <a href="/search/cond-mat?searchtype=author&query=Rohlf%2C+S">Sebastian Rohlf</a>, <a href="/search/cond-mat?searchtype=author&query=Kall%C3%A4ne%2C+M">Matthias Kall盲ne</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Gould%2C+C">Charles Gould</a> , et al. (5 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2001.05541v1-abstract-short" style="display: inline;"> Since the discovery of the quantum anomalous Hall effect in the magnetically doped topological insulators (MTI) Cr:(Bi,Sb)$_2$Te$_3$ and V:(Bi,Sb)$_2$Te$_3$, the search for the exchange coupling mechanisms underlying the onset of ferromagnetism has been a central issue, and a variety of different scenarios have been put forward. By combining resonant photoemission, X-ray magnetic dichroism and mul… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.05541v1-abstract-full').style.display = 'inline'; document.getElementById('2001.05541v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2001.05541v1-abstract-full" style="display: none;"> Since the discovery of the quantum anomalous Hall effect in the magnetically doped topological insulators (MTI) Cr:(Bi,Sb)$_2$Te$_3$ and V:(Bi,Sb)$_2$Te$_3$, the search for the exchange coupling mechanisms underlying the onset of ferromagnetism has been a central issue, and a variety of different scenarios have been put forward. By combining resonant photoemission, X-ray magnetic dichroism and multiplet ligand field theory, we determine the local electronic and magnetic configurations of V and Cr impurities in (Bi,Sb)$_2$Te$_3$. While strong pd hybridisation is found for both dopant types, their 3d densities of states show pronounced differences. State-of-the-art first-principles calculations show how these impurity states mediate characteristic short-range pd exchange interactions, whose strength sensitively varies with the position of the 3d states relative to the Fermi level. Measurements on films with varying host stoichiometry support this trend. Our results establish the essential role of impurity-state mediated exchange interactions in the magnetism of MTI. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.05541v1-abstract-full').style.display = 'none'; document.getElementById('2001.05541v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 15 January, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Npj Quantum Materials 5, 87 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1909.10793">arXiv:1909.10793</a> <span> [<a href="https://arxiv.org/pdf/1909.10793">pdf</a>, <a href="https://arxiv.org/format/1909.10793">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> </div> <p class="title is-5 mathjax"> Structural Dynamics of incommensurate Charge-Density Waves tracked by Ultrafast Low-Energy Electron Diffraction </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Storeck%2C+G">Gero Storeck</a>, <a href="/search/cond-mat?searchtype=author&query=Horstmann%2C+J+G">Jan Gerrit Horstmann</a>, <a href="/search/cond-mat?searchtype=author&query=Diekmann%2C+T">Theo Diekmann</a>, <a href="/search/cond-mat?searchtype=author&query=Vogelgesang%2C+S">Simon Vogelgesang</a>, <a href="/search/cond-mat?searchtype=author&query=von+Witte%2C+G">Gevin von Witte</a>, <a href="/search/cond-mat?searchtype=author&query=Yalunin%2C+S">Sergej Yalunin</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Ropers%2C+C">Claus Ropers</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1909.10793v2-abstract-short" style="display: inline;"> We study the non-equilibrium structural dynamics of the incommensurate and nearly-commensurate charge-density wave phases in 1T-TaS$_2$. Employing ultrafast low-energy electron diffraction (ULEED) with 1 ps temporal resolution, we investigate the ultrafast quench and recovery of the CDW-coupled periodic lattice distortion. Sequential structural relaxation processes are observed by tracking the int… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1909.10793v2-abstract-full').style.display = 'inline'; document.getElementById('1909.10793v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1909.10793v2-abstract-full" style="display: none;"> We study the non-equilibrium structural dynamics of the incommensurate and nearly-commensurate charge-density wave phases in 1T-TaS$_2$. Employing ultrafast low-energy electron diffraction (ULEED) with 1 ps temporal resolution, we investigate the ultrafast quench and recovery of the CDW-coupled periodic lattice distortion. Sequential structural relaxation processes are observed by tracking the intensities of main lattice as well as satellite diffraction peaks as well as the diffuse scattering background. Comparing distinct groups of diffraction peaks, we disentangle the ultrafast quench of the PLD amplitude from phonon-related reductions of the diffraction intensity. Fluence-dependent relaxation cycles reveal a long-lived partial suppression of the order parameter for up to 60 picoseconds, far outlasting the initial amplitude recovery and electron-phonon scattering times. This delayed return to a quasi-thermal level is controlled by lattice thermalization and coincides with the population of zone-center acoustic modes, as evidenced by a structured diffuse background. The long-lived non-equilibrium order parameter suppression suggests hot populations of CDW-coupled lattice modes. Finally, a broadening of the superlattice peaks is observed at high fluences, pointing to a nonlinear generation of phase fluctuations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1909.10793v2-abstract-full').style.display = 'none'; document.getElementById('1909.10793v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 27 May, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 24 September, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Main text and Appendices</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1907.11677">arXiv:1907.11677</a> <span> [<a href="https://arxiv.org/pdf/1907.11677">pdf</a>, <a href="https://arxiv.org/format/1907.11677">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevResearch.2.022046">10.1103/PhysRevResearch.2.022046 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Doublon bottleneck in the ultrafast relaxation dynamics of hot electrons in 1T-TaS_2 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Avigo%2C+I">Isabella Avigo</a>, <a href="/search/cond-mat?searchtype=author&query=Queisser%2C+F">Friedemann Queisser</a>, <a href="/search/cond-mat?searchtype=author&query=Zhou%2C+P">Ping Zhou</a>, <a href="/search/cond-mat?searchtype=author&query=Ligges%2C+M">Manuel Ligges</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Sch%C3%BCtzhold%2C+R">Ralf Sch眉tzhold</a>, <a href="/search/cond-mat?searchtype=author&query=Bovensiepen%2C+U">Uwe Bovensiepen</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1907.11677v1-abstract-short" style="display: inline;"> Employing time-resolved photoelectron spectroscopy we analyze the relaxation dynamics of hot electrons in the charge density wave / Mott material 1T-TaS_2. At 1.2 eV above the Fermi level we observe a hot electron lifetime of 12 +- 5 fs in the metallic state and of 60 +- 10 fs in the broken symmetry ground state - a direct consequence of the reduced phase space for electron-electron scattering det… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1907.11677v1-abstract-full').style.display = 'inline'; document.getElementById('1907.11677v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1907.11677v1-abstract-full" style="display: none;"> Employing time-resolved photoelectron spectroscopy we analyze the relaxation dynamics of hot electrons in the charge density wave / Mott material 1T-TaS_2. At 1.2 eV above the Fermi level we observe a hot electron lifetime of 12 +- 5 fs in the metallic state and of 60 +- 10 fs in the broken symmetry ground state - a direct consequence of the reduced phase space for electron-electron scattering determined by the Mott gap. Boltzmann equation calculations which account for the interaction of hot electrons in a Bloch band with a doublon-holon excitation in the Mott state provide insight into the unoccupied electronic structure in the correlated state. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1907.11677v1-abstract-full').style.display = 'none'; document.getElementById('1907.11677v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 26 July, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">6 pages, 3 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Research 2, 022046 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1907.11610">arXiv:1907.11610</a> <span> [<a href="https://arxiv.org/pdf/1907.11610">pdf</a>, <a href="https://arxiv.org/format/1907.11610">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41467-020-15079-1">10.1038/s41467-020-15079-1 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Collapse of layer dimerization in the photo-induced hidden state of 1T-TaS2 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Stahl%2C+Q">Quirin Stahl</a>, <a href="/search/cond-mat?searchtype=author&query=Kusch%2C+M">Maximilian Kusch</a>, <a href="/search/cond-mat?searchtype=author&query=Heinsch%2C+F">Florian Heinsch</a>, <a href="/search/cond-mat?searchtype=author&query=Garbarino%2C+G">Gaston Garbarino</a>, <a href="/search/cond-mat?searchtype=author&query=Kretzschmar%2C+N">Norman Kretzschmar</a>, <a href="/search/cond-mat?searchtype=author&query=Hanff%2C+K">Kerstin Hanff</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Geck%2C+J">Jochen Geck</a>, <a href="/search/cond-mat?searchtype=author&query=Ritschel%2C+T">Tobias Ritschel</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1907.11610v2-abstract-short" style="display: inline;"> Photo-induced switching between collective quantum states of matter is a fascinating rising field with exciting opportunities for novel technologies. Presently very intensively studied examples in this regard are nanometer-thick single crystals of the layered material 1T-TaS2 , where picosecond laser pulses can trigger a fully reversible insulator-to-metal transition (IMT). This IMT is believed to… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1907.11610v2-abstract-full').style.display = 'inline'; document.getElementById('1907.11610v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1907.11610v2-abstract-full" style="display: none;"> Photo-induced switching between collective quantum states of matter is a fascinating rising field with exciting opportunities for novel technologies. Presently very intensively studied examples in this regard are nanometer-thick single crystals of the layered material 1T-TaS2 , where picosecond laser pulses can trigger a fully reversible insulator-to-metal transition (IMT). This IMT is believed to be connected to the switching between metastable collective quantum states, but the microscopic nature of this so-called hidden quantum state remained largely elusive up to now. Here we determine the latter by means of state-of-the-art x-ray diffraction and show that the laser-driven IMT involves a marked rearrangement of the charge and orbital order in the direction perpendicular to the TaS2-layers. More specifically, we identify the collapse of inter-layer molecular orbital dimers, which are a characteristic feature of the insulating phase, as a key mechanism for the non-thermal IMT in 1T-TaS2, which indeed involves a collective transition between two truly long-range ordered electronic crystals. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1907.11610v2-abstract-full').style.display = 'none'; document.getElementById('1907.11610v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 25 March, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 26 July, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Nat Commun 11, 1247 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1907.10553">arXiv:1907.10553</a> <span> [<a href="https://arxiv.org/pdf/1907.10553">pdf</a>, <a href="https://arxiv.org/format/1907.10553">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevLett.123.236802">10.1103/PhysRevLett.123.236802 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Larger than 80$\,$% Valley Polarization of Free Carriers in Singly-Oriented Single Layer WS$_2$ on Au(111) </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Beyer%2C+H">H. Beyer</a>, <a href="/search/cond-mat?searchtype=author&query=Rohde%2C+G">G. Rohde</a>, <a href="/search/cond-mat?searchtype=author&query=%C4%8Cabo%2C+A+G">A. Grubi拧i膰膶abo</a>, <a href="/search/cond-mat?searchtype=author&query=Stange%2C+A">A. Stange</a>, <a href="/search/cond-mat?searchtype=author&query=Jacobsen%2C+T">T. Jacobsen</a>, <a href="/search/cond-mat?searchtype=author&query=Bignardi%2C+L">L. Bignardi</a>, <a href="/search/cond-mat?searchtype=author&query=Lizzit%2C+D">D. Lizzit</a>, <a href="/search/cond-mat?searchtype=author&query=Lacovig%2C+P">P. Lacovig</a>, <a href="/search/cond-mat?searchtype=author&query=Sanders%2C+C+E">C. E. Sanders</a>, <a href="/search/cond-mat?searchtype=author&query=Lizzit%2C+S">S. Lizzit</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">K. Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Hofmann%2C+P">P. Hofmann</a>, <a href="/search/cond-mat?searchtype=author&query=Bauer%2C+M">M. Bauer</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1907.10553v1-abstract-short" style="display: inline;"> We employ time- and angle-resolved photoemission spectroscopy to study the spin- and valley-selective photoexcitation and dynamics of free carriers at the K and K' points in singly-oriented single layer WS$_2$/Au(111). Our results reveal that in the valence band maximum an ultimate valley polarization of free holes of 84$\,$% can be achieved upon excitation with circularly polarized light at room… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1907.10553v1-abstract-full').style.display = 'inline'; document.getElementById('1907.10553v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1907.10553v1-abstract-full" style="display: none;"> We employ time- and angle-resolved photoemission spectroscopy to study the spin- and valley-selective photoexcitation and dynamics of free carriers at the K and K' points in singly-oriented single layer WS$_2$/Au(111). Our results reveal that in the valence band maximum an ultimate valley polarization of free holes of 84$\,$% can be achieved upon excitation with circularly polarized light at room temperature. Notably, we observe a significantly smaller valley polarization for the photoexcited free electrons in the conduction band minimum. Clear differences in the carrier dynamics between electrons and holes imply intervalley scattering processes into dark states being responsible for the efficient depolarization of the excited electron population. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1907.10553v1-abstract-full').style.display = 'none'; document.getElementById('1907.10553v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 July, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">13 pages, 7 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 123, 236802 (2019) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1906.12155">arXiv:1906.12155</a> <span> [<a href="https://arxiv.org/pdf/1906.12155">pdf</a>, <a href="https://arxiv.org/format/1906.12155">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1063/1.5118777">10.1063/1.5118777 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Time- and momentum-resolved photoemission studies using time-of-flight momentum microscopy at a free-electron laser </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Kutnyakhov%2C+D">Dmytro Kutnyakhov</a>, <a href="/search/cond-mat?searchtype=author&query=Xian%2C+R+P">Rui Patrick Xian</a>, <a href="/search/cond-mat?searchtype=author&query=Dendzik%2C+M">Maciej Dendzik</a>, <a href="/search/cond-mat?searchtype=author&query=Heber%2C+M">Michael Heber</a>, <a href="/search/cond-mat?searchtype=author&query=Pressacco%2C+F">Federico Pressacco</a>, <a href="/search/cond-mat?searchtype=author&query=Agustsson%2C+S+Y">Steinn Ymir Agustsson</a>, <a href="/search/cond-mat?searchtype=author&query=Wenthaus%2C+L">Lukas Wenthaus</a>, <a href="/search/cond-mat?searchtype=author&query=Meyer%2C+H">Holger Meyer</a>, <a href="/search/cond-mat?searchtype=author&query=Gieschen%2C+S">Sven Gieschen</a>, <a href="/search/cond-mat?searchtype=author&query=Mercurio%2C+G">Giuseppe Mercurio</a>, <a href="/search/cond-mat?searchtype=author&query=Benz%2C+A">Adrian Benz</a>, <a href="/search/cond-mat?searchtype=author&query=B%C3%BChlman%2C+K">Kevin B眉hlman</a>, <a href="/search/cond-mat?searchtype=author&query=D%C3%A4ster%2C+S">Simon D盲ster</a>, <a href="/search/cond-mat?searchtype=author&query=Gort%2C+R">Rafael Gort</a>, <a href="/search/cond-mat?searchtype=author&query=Curcio%2C+D">Davide Curcio</a>, <a href="/search/cond-mat?searchtype=author&query=Volckaert%2C+K">Klara Volckaert</a>, <a href="/search/cond-mat?searchtype=author&query=Bianchi%2C+M">Marco Bianchi</a>, <a href="/search/cond-mat?searchtype=author&query=Sanders%2C+C">Charlotte Sanders</a>, <a href="/search/cond-mat?searchtype=author&query=Miwa%2C+J+A">Jill Atsuko Miwa</a>, <a href="/search/cond-mat?searchtype=author&query=Ulstrup%2C+S">S酶ren Ulstrup</a>, <a href="/search/cond-mat?searchtype=author&query=Oelsner%2C+A">Andreas Oelsner</a>, <a href="/search/cond-mat?searchtype=author&query=Tusche%2C+C">Christian Tusche</a>, <a href="/search/cond-mat?searchtype=author&query=Chen%2C+Y">Ying-Jiun Chen</a>, <a href="/search/cond-mat?searchtype=author&query=Vasilyev%2C+D">Dmitrii Vasilyev</a>, <a href="/search/cond-mat?searchtype=author&query=Medjanik%2C+K">Katerina Medjanik</a> , et al. (16 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1906.12155v3-abstract-short" style="display: inline;"> Time-resolved photoemission with ultrafast pump and probe pulses is an emerging technique with wide application potential. Real-time recording of non-equilibrium electronic processes, transient states in chemical reactions or the interplay of electronic and structural dynamics offers fascinating opportunities for future research. Combining valence-band and core-level spectroscopy with photoelectro… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1906.12155v3-abstract-full').style.display = 'inline'; document.getElementById('1906.12155v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1906.12155v3-abstract-full" style="display: none;"> Time-resolved photoemission with ultrafast pump and probe pulses is an emerging technique with wide application potential. Real-time recording of non-equilibrium electronic processes, transient states in chemical reactions or the interplay of electronic and structural dynamics offers fascinating opportunities for future research. Combining valence-band and core-level spectroscopy with photoelectron diffraction for electronic, chemical and structural analysis requires few 10 fs soft X-ray pulses with some 10 meV spectral resolution, which are currently available at high repetition rate free-electron lasers. The PG2 beamline at FLASH (DESY, Hamburg) provides a high pulse rate of 5000 pulses/s, 60 fs pulse duration and 40 meV bandwidth in an energy range of 25-830 eV with a photon beam size down to 50 microns in diameter. We have constructed and optimized a versatile setup commissioned at FLASH/PG2 that combines FEL capabilities together with a multidimensional recording scheme for photoemission studies. We use a full-field imaging momentum microscope with time-of-flight energy recording as the detector for mapping of 3D band structures in ($k_x$, $k_y$, $E$) parameter space with unprecedented efficiency. Our instrument can image full surface Brillouin zones with up to 7 脜 $^{-1}$ diameter in a binding-energy range of several eV, resolving about $2.5\times10^5$ data voxels. As an example, we present results for the ultrafast excited state dynamics in the model van der Waals semiconductor WSe$_2$. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1906.12155v3-abstract-full').style.display = 'none'; document.getElementById('1906.12155v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 18 September, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 28 June, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Review of Scientific Instruments 91, 013109 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1906.09545">arXiv:1906.09545</a> <span> [<a href="https://arxiv.org/pdf/1906.09545">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1073/pnas.1917341117">10.1073/pnas.1917341117 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Coherent modulation of the electron temperature and electron-phonon couplings in a 2D material </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Zhang%2C+Y">Yingchao Zhang</a>, <a href="/search/cond-mat?searchtype=author&query=Shi%2C+X">Xun Shi</a>, <a href="/search/cond-mat?searchtype=author&query=You%2C+W">Wenjing You</a>, <a href="/search/cond-mat?searchtype=author&query=Tao%2C+Z">Zhensheng Tao</a>, <a href="/search/cond-mat?searchtype=author&query=Zhong%2C+Y">Yigui Zhong</a>, <a href="/search/cond-mat?searchtype=author&query=Kabeer%2C+F+C">Fairoja Cheenicode Kabeer</a>, <a href="/search/cond-mat?searchtype=author&query=Maldonado%2C+P">Pablo Maldonado</a>, <a href="/search/cond-mat?searchtype=author&query=Oppeneer%2C+P+M">Peter M. Oppeneer</a>, <a href="/search/cond-mat?searchtype=author&query=Bauer%2C+M">Michael Bauer</a>, <a href="/search/cond-mat?searchtype=author&query=Rossnagel%2C+K">Kai Rossnagel</a>, <a href="/search/cond-mat?searchtype=author&query=Kapteyn%2C+H">Henry Kapteyn</a>, <a href="/search/cond-mat?searchtype=author&query=Murnane%2C+M">Margaret Murnane</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1906.09545v1-abstract-short" style="display: inline;"> Ultrashort light pulses can selectively excite charges, spins and phonons in materials, providing a powerful approach for manipulating their properties. Here we use femtosecond laser pulses to coherently manipulate the electron and phonon distributions, and their couplings, in the charge density wave (CDW) material 1T-TaSe$_2$. After exciting the material with a short light pulse, spatial smearing… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1906.09545v1-abstract-full').style.display = 'inline'; document.getElementById('1906.09545v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1906.09545v1-abstract-full" style="display: none;"> Ultrashort light pulses can selectively excite charges, spins and phonons in materials, providing a powerful approach for manipulating their properties. Here we use femtosecond laser pulses to coherently manipulate the electron and phonon distributions, and their couplings, in the charge density wave (CDW) material 1T-TaSe$_2$. After exciting the material with a short light pulse, spatial smearing of the electrons launches a coherent lattice breathing mode, which in turn modulates the electron temperature. This indicates a bi-directional energy exchange between the electrons and the strongly-coupled phonons. By tuning the laser excitation fluence, we can control the magnitude of the electron temperature modulation, from ~ 200 K in the case of weak excitation, to ~ 1000 K for strong laser excitation. This is accompanied by a switching of the dominant mechanism from anharmonic phonon-phonon coupling to coherent electron-phonon coupling, as manifested by a phase change of $蟺$ in the electron temperature modulation. Our approach thus opens up possibilities for coherently manipulating the interactions and properties of quasi-2D and other quantum materials using light. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1906.09545v1-abstract-full').style.display = 'none'; document.getElementById('1906.09545v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 22 June, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">15 pages, 4 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Proceedings of the National Academy of Sciences 117, 8788 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1903.11826">arXiv:1903.11826</a> <span> [<a href="https://arxiv.org/pdf/1903.11826">pdf</a>, <a href="https://arxiv.org/format/1903.11826">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1103/PhysRevB.100.121104">10.1103/PhysRevB.100.121104 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Surface states and Rashba-type spin polarization in antiferromagnetic MnBi$_2$Te$_4$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Vidal%2C+R+C">R. C. Vidal</a>, <a href="/search/cond-mat?searchtype=author&query=Bentmann%2C+H">H. Bentmann</a>, <a href="/search/cond-mat?searchtype=author&query=Peixoto%2C+T+R+F">T. R. F. Peixoto</a>, <a href="/search/cond-mat?searchtype=author&query=Zeugner%2C+A">A. Zeugner</a>, <a href="/search/cond-mat?searchtype=author&query=Moser%2C+S">S. Moser</a>, <a href="/search/cond-mat?searchtype=author&query=Min%2C+C+H">C. H. Min</a>, <a href="/search/cond-mat?searchtype=author&query=Schatz%2C+S">S. Schatz</a>, <a href="/search/cond-mat?searchtype=author&query=Kissner%2C+K">K. Kissner</a>, <a href="/search/cond-mat?searchtype=author&query=%C3%9Cnzelmann%2C+M">M. 脺nzelmann</a>, <a href="/search/cond-mat?searchtype=author&query=Fornari%2C+C+I">C. I. Fornari</a>, <a href="/search/cond-mat?searchtype=author&query=Vasili%2C+H+B">H. B. Vasili</a>, <a href="/search/cond-mat?searchtype=author&query=Valvidares%2C+M">M. Valvidares</a>, <a href="/search/cond-mat?searchtype=author&query=Sakamoto%2C+K">K. Sakamoto</a>, <a href="/search/cond-mat?searchtype=author&query=Mondal%2C+D">D. Mondal</a>, <a href="/search/cond-mat?searchtype=author&query=Fujii%2C+J">J. Fujii</a>, <a href="/search/cond-mat?searchtype=author&query=Vobornik%2C+I">I. Vobornik</a>, <a href="/search/cond-mat?searchtype=author&query=Jung%2C+S">S. Jung</a>, <a href="/search/cond-mat?searchtype=author&query=Cacho%2C+C">C. Cacho</a>, <a href="/search/cond-mat?searchtype=author&query=Kim%2C+T+K">T. K. Kim</a>, <a href="/search/cond-mat?searchtype=author&query=Koch%2C+R+J">R. J. Koch</a>, <a href="/search/cond-mat?searchtype=author&query=Jozwiak%2C+C">C. Jozwiak</a>, <a href="/search/cond-mat?searchtype=author&query=Bostwick%2C+A">A. Bostwick</a>, <a href="/search/cond-mat?searchtype=author&query=Denlinger%2C+J+D">J. D. Denlinger</a>, <a href="/search/cond-mat?searchtype=author&query=Rotenberg%2C+E">E. Rotenberg</a>, <a href="/search/cond-mat?searchtype=author&query=Buck%2C+J">J. Buck</a> , et al. (10 additional authors not shown) </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1903.11826v2-abstract-short" style="display: inline;"> The layered van der Waals antiferromagnet MnBi$_2$Te$_4$ has been predicted to combine the band ordering of archetypical topological insulators such as Bi$_2$Te$_3$ with the magnetism of Mn, making this material a viable candidate for the realization of various magnetic topological states. We have systematically investigated the surface electronic structure of MnBi$_2$Te$_4$(0001) single crystals… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1903.11826v2-abstract-full').style.display = 'inline'; document.getElementById('1903.11826v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1903.11826v2-abstract-full" style="display: none;"> The layered van der Waals antiferromagnet MnBi$_2$Te$_4$ has been predicted to combine the band ordering of archetypical topological insulators such as Bi$_2$Te$_3$ with the magnetism of Mn, making this material a viable candidate for the realization of various magnetic topological states. We have systematically investigated the surface electronic structure of MnBi$_2$Te$_4$(0001) single crystals by use of spin- and angle-resolved photoelectron spectroscopy experiments. In line with theoretical predictions, the results reveal a surface state in the bulk band gap and they provide evidence for the influence of exchange interaction and spin-orbit coupling on the surface electronic structure. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1903.11826v2-abstract-full').style.display = 'none'; document.getElementById('1903.11826v2-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 12 September, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 28 March, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">Revised version</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. 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