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<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=Lang%2C+M&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Lang%2C+M&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Lang%2C+M&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> <li> <a href="/search/?searchtype=author&query=Lang%2C+M&start=100" class="pagination-link " aria-label="Page 3" aria-current="page">3 </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/2409.13836">arXiv:2409.13836</a> <span> [<a href="https://arxiv.org/pdf/2409.13836">pdf</a>, <a href="https://arxiv.org/format/2409.13836">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"> Ferroelectric and Multiferroic Properties of Quasi-2D Organic Charge-Transfer Salts </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Lunkenheimer%2C+P">Peter Lunkenheimer</a>, <a href="/search/cond-mat?searchtype=author&query=Ganter%2C+O">Owen Ganter</a>, <a href="/search/cond-mat?searchtype=author&query=Winter%2C+S">Steve Winter</a>, <a href="/search/cond-mat?searchtype=author&query=M%C3%BCller%2C+J">Jens M眉ller</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="2409.13836v1-abstract-short" style="display: inline;"> In conventional ferroelectrics the electric dipoles are generated by off-center displacements of ions. In recent years, a new type of so-called electronic ferroelectrics has attracted great attention, where the polarization is driven by electronic degrees of freedom. Of particular interest are materials with strong electronic correlations, featuring a variety of intriguing phenomena and instabilit… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.13836v1-abstract-full').style.display = 'inline'; document.getElementById('2409.13836v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2409.13836v1-abstract-full" style="display: none;"> In conventional ferroelectrics the electric dipoles are generated by off-center displacements of ions. In recent years, a new type of so-called electronic ferroelectrics has attracted great attention, where the polarization is driven by electronic degrees of freedom. Of particular interest are materials with strong electronic correlations, featuring a variety of intriguing phenomena and instabilities, which may interact with or even induce electronic ferroelectricity. In this review, we will focus on the class of strongly correlated charge-transfer salts, where electronic ferroelectricity was suggested by theory and has been confirmed by numerous experiments. The paper summarizes some basic physical properties of various relevant quasi-two dimensional salts and gives some background on the experimental tools applied to establish ferroelectricity. We discuss the key experimental observations, including the exciting discovery of multiferroicity, and provide some theoretical considerations on the magnetoelectric couplings that are of relevance here. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2409.13836v1-abstract-full').style.display = 'none'; document.getElementById('2409.13836v1-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 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2408.00401">arXiv:2408.00401</a> <span> [<a href="https://arxiv.org/pdf/2408.00401">pdf</a>, <a href="https://arxiv.org/format/2408.00401">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Superconductivity">cond-mat.supr-con</span> </div> </div> <p class="title is-5 mathjax"> Persistence of small polarons into the superconducting phase of Ba$_{1-x}$K$_x$BiO$_3$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Naamneh%2C+M">Muntaser Naamneh</a>, <a href="/search/cond-mat?searchtype=author&query=Paris%2C+E">Eugenio Paris</a>, <a href="/search/cond-mat?searchtype=author&query=McNally%2C+D">Daniel McNally</a>, <a href="/search/cond-mat?searchtype=author&query=Tseng%2C+Y">Yi Tseng</a>, <a href="/search/cond-mat?searchtype=author&query=Pudelko%2C+W+R">Wojciech R. Pudelko</a>, <a href="/search/cond-mat?searchtype=author&query=Gawryluk%2C+D+J">Dariusz J. Gawryluk</a>, <a href="/search/cond-mat?searchtype=author&query=Shamblin%2C+J">J. Shamblin</a>, <a href="/search/cond-mat?searchtype=author&query=OQuinn%2C+E">Eric OQuinn</a>, <a href="/search/cond-mat?searchtype=author&query=Cohen-Stead%2C+B">Benjamin Cohen-Stead</a>, <a href="/search/cond-mat?searchtype=author&query=Shi%2C+M">Ming Shi</a>, <a href="/search/cond-mat?searchtype=author&query=Radovic%2C+M">Milan Radovic</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">M. Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Schmitt%2C+T">Thorsten Schmitt</a>, <a href="/search/cond-mat?searchtype=author&query=Johnston%2C+S">Steven Johnston</a>, <a href="/search/cond-mat?searchtype=author&query=Plumb%2C+N+C">Nicholas C. Plumb</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="2408.00401v1-abstract-short" style="display: inline;"> Bipolaronic superconductivity is an exotic pairing mechanism proposed for materials like Ba$_{1-x}$K$_x$BiO$_3$ (BKBO); however, conclusive experimental evidence for a (bi)polaron metallic state in this material remains elusive. Here, we combine resonant inelastic x-ray and neutron total scattering techniques with advanced modelling to study the local lattice distortions, electronic structure, and… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.00401v1-abstract-full').style.display = 'inline'; document.getElementById('2408.00401v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2408.00401v1-abstract-full" style="display: none;"> Bipolaronic superconductivity is an exotic pairing mechanism proposed for materials like Ba$_{1-x}$K$_x$BiO$_3$ (BKBO); however, conclusive experimental evidence for a (bi)polaron metallic state in this material remains elusive. Here, we combine resonant inelastic x-ray and neutron total scattering techniques with advanced modelling to study the local lattice distortions, electronic structure, and electron-phonon coupling ($e$-ph) in BKBO as a function of doping. Data for the parent compound ($x = 0$) indicates that the electronic gap opens in predominantly oxygen-derived states strongly coupled to a long-range ordered breathing distortion of the oxygen sublattice. Upon doping, short-range breathing distortions and sizable ($e$-ph) coupling persist into the superconducting regime ($x = 0.4$). Comparisons with exact diagonalization and determinant quantum Monte Carlo calculations further support this conclusion. Our results provide compelling evidence that BKBO's metallic phase hosts a liquid of small (bi)polarons derived from local breathing distortions of the lattice, with implications for understanding the low-temperature superconducting instability <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2408.00401v1-abstract-full').style.display = 'none'; document.getElementById('2408.00401v1-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 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/2402.03986">arXiv:2402.03986</a> <span> [<a href="https://arxiv.org/pdf/2402.03986">pdf</a>, <a href="https://arxiv.org/ps/2402.03986">ps</a>, <a href="https://arxiv.org/format/2402.03986">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/PhysRevMaterials.8.074404">10.1103/PhysRevMaterials.8.074404 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Two-step growth of high-quality single crystals of the Kitaev magnet $伪$-RuCl$_{3}$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Namba%2C+R">R. Namba</a>, <a href="/search/cond-mat?searchtype=author&query=Imamura%2C+K">K. Imamura</a>, <a href="/search/cond-mat?searchtype=author&query=Ishioka%2C+R">R. Ishioka</a>, <a href="/search/cond-mat?searchtype=author&query=Ishihara%2C+K">K. Ishihara</a>, <a href="/search/cond-mat?searchtype=author&query=Miyamoto%2C+T">T. Miyamoto</a>, <a href="/search/cond-mat?searchtype=author&query=Okamoto%2C+H">H. Okamoto</a>, <a href="/search/cond-mat?searchtype=author&query=Shimizu%2C+Y">Y. Shimizu</a>, <a href="/search/cond-mat?searchtype=author&query=Saito%2C+Y">Y. Saito</a>, <a href="/search/cond-mat?searchtype=author&query=Agarmani%2C+Y">Y. Agarmani</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">M. Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Murayama%2C+H">H. Murayama</a>, <a href="/search/cond-mat?searchtype=author&query=Xing%2C+Y">Y. Xing</a>, <a href="/search/cond-mat?searchtype=author&query=Suetsugu%2C+S">S. Suetsugu</a>, <a href="/search/cond-mat?searchtype=author&query=Kasahara%2C+Y">Y. Kasahara</a>, <a href="/search/cond-mat?searchtype=author&query=Matsuda%2C+Y">Y. Matsuda</a>, <a href="/search/cond-mat?searchtype=author&query=Hashimoto%2C+K">K. Hashimoto</a>, <a href="/search/cond-mat?searchtype=author&query=Shibauchi%2C+T">T. Shibauchi</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="2402.03986v2-abstract-short" style="display: inline;"> The layered honeycomb magnet $伪$-RuCl$_3$ is the most promising candidate for a Kitaev quantum spin liquid (KQSL) that can host charge-neutral Majorana fermions. Recent studies have shown significant sample dependence of thermal transport properties, which are a key probe of Majorana quasiparticles in the KQSL state, highlighting the importance of preparing high-quality single crystals of $伪$-RuCl… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.03986v2-abstract-full').style.display = 'inline'; document.getElementById('2402.03986v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2402.03986v2-abstract-full" style="display: none;"> The layered honeycomb magnet $伪$-RuCl$_3$ is the most promising candidate for a Kitaev quantum spin liquid (KQSL) that can host charge-neutral Majorana fermions. Recent studies have shown significant sample dependence of thermal transport properties, which are a key probe of Majorana quasiparticles in the KQSL state, highlighting the importance of preparing high-quality single crystals of $伪$-RuCl$_3$. Here, we present a relatively simple and reliable method to grow high-quality single crystals of $伪$-RuCl$_3$. We use a two-step crystal growth method consisting of a purification process by chemical vapor transport (CVT) and a main crystal growth process by sublimation. The obtained crystals exhibit a distinct first-order structural phase transition from the monoclinic ($C2/m$) to the rhombohedral ($R\bar{3}$) structure at $\sim150$ K, which is confirmed by the nuclear quadrupole resonance spectra with much sharper widths than previously reported. The Raman spectra show the absence of defect-induced modes, supporting the good crystallinity of our samples. The jumps in the thermal expansion coefficient and specific heat at the antiferromagnetic (AFM) transition at 7.6-7.7 K are larger and sharper than those of previous samples grown by the CVT and Bridgman methods and do not show any additional AFM transitions at 10-14 K due to stacking faults. The longitudinal thermal conductivity in the AFM phase is significantly larger than previously reported, indicating a very long mean free path of heat carriers. All the results indicate that our single crystals are of superior quality with good crystallinity and few stacking faults, which provides a suitable platform for studying the Kitaev physics. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2402.03986v2-abstract-full').style.display = 'none'; document.getElementById('2402.03986v2-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 September, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 6 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">9 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. Materials 8, 074404 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2310.18761">arXiv:2310.18761</a> <span> [<a href="https://arxiv.org/pdf/2310.18761">pdf</a>, <a href="https://arxiv.org/format/2310.18761">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"> Ultrafast gap dynamics upon photodoping the Mott-insulating phase of a two-dimensional organic charge-transfer salt </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Warawa%2C+K">Konstantin Warawa</a>, <a href="/search/cond-mat?searchtype=author&query=Agarmani%2C+Y">Yassine Agarmani</a>, <a href="/search/cond-mat?searchtype=author&query=Schubert%2C+H">Harald Schubert</a>, <a href="/search/cond-mat?searchtype=author&query=Dressel%2C+M">Martin Dressel</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Roskos%2C+H+G">Hartmut G. Roskos</a>, <a href="/search/cond-mat?searchtype=author&query=Thomson%2C+M+D">Mark D. Thomson</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="2310.18761v1-abstract-short" style="display: inline;"> We investigate experimentally the ultrafast changes in the spectral response of the Mott insulator $魏$-(BEDT-TTF)$_2$Cu[N(CN)$_2$]Cl ($魏$-Cl) upon photodoping with intense excitation at 1.6 eV and probing with continuum pulses simultaneously covering both the terahertz and infrared (IR) ranges (from 0 to 0.6 eV). A quantitative analysis of the differential reflectivity using a multi-band Lorentzia… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.18761v1-abstract-full').style.display = 'inline'; document.getElementById('2310.18761v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.18761v1-abstract-full" style="display: none;"> We investigate experimentally the ultrafast changes in the spectral response of the Mott insulator $魏$-(BEDT-TTF)$_2$Cu[N(CN)$_2$]Cl ($魏$-Cl) upon photodoping with intense excitation at 1.6 eV and probing with continuum pulses simultaneously covering both the terahertz and infrared (IR) ranges (from 0 to 0.6 eV). A quantitative analysis of the differential reflectivity using a multi-band Lorentzian model provide absolute changes in spectral weights and objective global time constants for the relaxation vs. temperature. The transient conductivity spectra deduced from the analysis suggest that the transient photoinduced spectral weight is dominated by a progressive closure of the Mott gap with increasing excitation density, i.e. due to changes in the inter-Hubbard-band absorption by the remaining singly occupied states. We critically examine this scenario compared to that proposed previously, whereby the low-energy spectral weight is attributed to a Drude-like response of photoexcited doublons/holons. We also consider the observed slowing down of the relaxation rate with increasing excitation density, and temperature dependence of the initial doublon/holon density in terms of the phonon-mediated gap recombination model. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.18761v1-abstract-full').style.display = 'none'; document.getElementById('2310.18761v1-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 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2310.17242">arXiv:2310.17242</a> <span> [<a href="https://arxiv.org/pdf/2310.17242">pdf</a>, <a href="https://arxiv.org/format/2310.17242">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"> Slow and Non-Equilibrium Dynamics due to Electronic Ferroelectricity in a Strongly-Correlated Molecular Conductor </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Thomas%2C+T">Tatjana Thomas</a>, <a href="/search/cond-mat?searchtype=author&query=Agarmani%2C+Y">Yassine Agarmani</a>, <a href="/search/cond-mat?searchtype=author&query=Hartmann%2C+S">Steffi Hartmann</a>, <a href="/search/cond-mat?searchtype=author&query=Kartsovnik%2C+M">Mark Kartsovnik</a>, <a href="/search/cond-mat?searchtype=author&query=Kushch%2C+N">Natalia Kushch</a>, <a href="/search/cond-mat?searchtype=author&query=Winter%2C+S+M">Stephen M. Winter</a>, <a href="/search/cond-mat?searchtype=author&query=Schmid%2C+S">Sebastian Schmid</a>, <a href="/search/cond-mat?searchtype=author&query=Lunkenheimer%2C+P">Peter Lunkenheimer</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Mueller%2C+J">Jens Mueller</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="2310.17242v2-abstract-short" style="display: inline;"> Using a combination of resistance fluctuation (noise) and dielectric spectroscopy we investigate the nature of relaxor-type electronic ferroelectricity in the organic conductor $魏$-(BETS)$_2$Mn[N(CN)$_2$]$_3$, a system representative for a wider class of materials, where strong correlations of electrons on a lattice of dimerized molecules results in an insulating ground state. The two complementar… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.17242v2-abstract-full').style.display = 'inline'; document.getElementById('2310.17242v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.17242v2-abstract-full" style="display: none;"> Using a combination of resistance fluctuation (noise) and dielectric spectroscopy we investigate the nature of relaxor-type electronic ferroelectricity in the organic conductor $魏$-(BETS)$_2$Mn[N(CN)$_2$]$_3$, a system representative for a wider class of materials, where strong correlations of electrons on a lattice of dimerized molecules results in an insulating ground state. The two complementary spectroscopies reveal a distinct low-frequency dynamics. By dielectric spectroscopy we detect an intrinsic relaxation that is typical for relaxor ferroelectrics below the metal-to-insulator transition at $T_{\rm{MI}}\sim 25\,$K. Resistance noise spectroscopy reveals fluctuating two-level processes above $T_{\rm MI}$ which strongly couple to the applied electric field, a signature of fluctuating polar nanoregions (PNR), i.e. clusters of quantum electric dipoles fluctuating collectively. The PNR preform above the metal insulator transition. Upon cooling through $T_{\rm MI}$, a drastic increase of the low-frequency $1/f$-type fluctuations and slowing down of the charge carrier dynamics is accompanied by the onset of strong non-equilibrium dynamics indicating a glassy transition of interacting dipolar clusters, the scaling properties of which are consistent with a droplet model. The freezing of nano-scale polar clusters and non-equilibrium dynamics is suggested to be a common feature of organic relaxor-type electronic ferroelectrics and needs to be considered in theoretical models describing these materials. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.17242v2-abstract-full').style.display = 'none'; document.getElementById('2310.17242v2-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 November, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 26 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2310.16637">arXiv:2310.16637</a> <span> [<a href="https://arxiv.org/pdf/2310.16637">pdf</a>, <a href="https://arxiv.org/format/2310.16637">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/10.1103/PhysRevResearch.6.023003">10.1103/PhysRevResearch.6.023003 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Combined experimental and theoretical studies on glasslike transitions in the frustrated molecular conductors $胃$-(BEDT-TTF)$_2MM'$(SCN)$_4$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Saito%2C+Y">Yohei Saito</a>, <a href="/search/cond-mat?searchtype=author&query=Ganter%2C+O">Owen Ganter</a>, <a href="/search/cond-mat?searchtype=author&query=Shang%2C+C">Chao Shang</a>, <a href="/search/cond-mat?searchtype=author&query=Hashimoto%2C+K">Kenichiro Hashimoto</a>, <a href="/search/cond-mat?searchtype=author&query=Sasaki%2C+T">Takahiko Sasaki</a>, <a href="/search/cond-mat?searchtype=author&query=Winter%2C+S+M">Stephen M. Winter</a>, <a href="/search/cond-mat?searchtype=author&query=M%C3%BCller%2C+J">Jens M眉ller</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</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="2310.16637v1-abstract-short" style="display: inline;"> We present results of the coefficient of thermal expansion for the frustrated quasi-two-dimensional molecular conductor $胃$-(BEDT-TTF)$_2$RbZn(SCN)$_4$ for temperatures 1.5 K $\leq T \leq$ 290 K. A pronounced first-order phase transition anomaly is observed at the combined charge-order/structural transition at 215 K. Furthermore, clear evidence is found for two separate glasslike transitions at… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.16637v1-abstract-full').style.display = 'inline'; document.getElementById('2310.16637v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.16637v1-abstract-full" style="display: none;"> We present results of the coefficient of thermal expansion for the frustrated quasi-two-dimensional molecular conductor $胃$-(BEDT-TTF)$_2$RbZn(SCN)$_4$ for temperatures 1.5 K $\leq T \leq$ 290 K. A pronounced first-order phase transition anomaly is observed at the combined charge-order/structural transition at 215 K. Furthermore, clear evidence is found for two separate glasslike transitions at $T_{\mathrm{g}}$ = 90-100 K and $T_{\mathrm{g}}^\dagger$ = 120-130 K, similar to previous findings for $胃$-(BEDT-TTF)$_2$CsZn(SCN)$_4$ and $胃$-(BEDT-TTF)$_2$CsCo(SCN)$_4$, reported in T. Thomas et al., Phys. Rev. B 105, L041114 (2022), both of which lack the charge-order/structural transition. Our findings indicate that these glasslike transitions are common features for the $胃$-(BEDT-TTF)$_2MM^\prime$(SCN)$_4$ family with $M$ = (Rb, Cs) and $M^\prime$ = (Co, Zn), irrespective of the presence or absence of charge order. These results are consistent with our model calculations on the glasslike dynamics associated with the flexible ethylene endgroups of the BEDT-TTF molecules for various $胃$-(BEDT-TTF)$_2MM^\prime$(SCN)$_4$ salts, predicting two different conformational glass transitions. Moreover, calculations of the hopping integrals show a substantial degree of dependence on the endgroups' conformation, suggesting a significant coupling to the electronic degrees of freedom. Our findings support the possibility that the glassy freezing of the ethylene endgroups could drive or enhance glassy charge dynamics. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.16637v1-abstract-full').style.display = 'none'; document.getElementById('2310.16637v1-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 October, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 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">11 pages, 10 figures, 1 table</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Research 6, 023003 (2024) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2307.10170">arXiv:2307.10170</a> <span> [<a href="https://arxiv.org/pdf/2307.10170">pdf</a>, <a href="https://arxiv.org/format/2307.10170">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="Computational Physics">physics.comp-ph</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/s41598-023-45111-5">10.1038/s41598-023-45111-5 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Controlling stable Bloch points with electric currents </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Martin Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Pathak%2C+S+A">Swapneel Amit Pathak</a>, <a href="/search/cond-mat?searchtype=author&query=Holt%2C+S+J+R">Samuel J. R. Holt</a>, <a href="/search/cond-mat?searchtype=author&query=Beg%2C+M">Marijan Beg</a>, <a href="/search/cond-mat?searchtype=author&query=Fangohr%2C+H">Hans Fangohr</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="2307.10170v1-abstract-short" style="display: inline;"> The Bloch point is a point singularity in the magnetisation configuration, where the magnetisation vanishes. It can exist as an equilibrium configuration and plays an important role in many magnetisation reversal processes. In the present work, we focus on manipulating Bloch points in a system that can host stable Bloch points - a two-layer FeGe nanostrip with opposite chirality of the two layers.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.10170v1-abstract-full').style.display = 'inline'; document.getElementById('2307.10170v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2307.10170v1-abstract-full" style="display: none;"> The Bloch point is a point singularity in the magnetisation configuration, where the magnetisation vanishes. It can exist as an equilibrium configuration and plays an important role in many magnetisation reversal processes. In the present work, we focus on manipulating Bloch points in a system that can host stable Bloch points - a two-layer FeGe nanostrip with opposite chirality of the two layers. We drive Bloch points using spin-transfer torques and find that Bloch points can move collectively without any Hall effect and report that Bloch points are repelled from the sample boundaries and each other. We study pinning of Bloch points at wedge-shaped constrictions (notches) in the nanostrip and demonstrate that arrays of Bloch points can be moved past a series of notches in a controlled manner by applying consecutive current pulses of different strength. Finally, we simulate a T-shaped geometry and demonstrate that a Bloch point can be moved along different paths by applying current between suitable strip ends. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2307.10170v1-abstract-full').style.display = 'none'; document.getElementById('2307.10170v1-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, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 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">12 pages, 7 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/2303.10091">arXiv:2303.10091</a> <span> [<a href="https://arxiv.org/pdf/2303.10091">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="Computational Physics">physics.comp-ph</span> </div> </div> <p class="title is-5 mathjax"> Energetics and Dynamics of a stable Bloch point </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Winkler%2C+T+B">Thomas Brian Winkler</a>, <a href="/search/cond-mat?searchtype=author&query=Beg%2C+M">Marijan Beg</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Martin Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Kl%C3%A4ui%2C+M">Mathias Kl盲ui</a>, <a href="/search/cond-mat?searchtype=author&query=Fangohr%2C+H">Hans Fangohr</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="2303.10091v1-abstract-short" style="display: inline;"> Magnetic Bloch points (BPs) are highly confined magnetization configurations, that often occur in transient spin dynamics processes. However, opposing chiralities of adjacent layers for instance in a FeGe bilayer stack can stabilize such magnetic BPs at the layer interface. These BPs configurations are metastable and consist of two coupled vortices (one in each layer) with same circularity and opp… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.10091v1-abstract-full').style.display = 'inline'; document.getElementById('2303.10091v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.10091v1-abstract-full" style="display: none;"> Magnetic Bloch points (BPs) are highly confined magnetization configurations, that often occur in transient spin dynamics processes. However, opposing chiralities of adjacent layers for instance in a FeGe bilayer stack can stabilize such magnetic BPs at the layer interface. These BPs configurations are metastable and consist of two coupled vortices (one in each layer) with same circularity and opposite polarity. Each vortex is stabilized by opposite sign Dzyaloshinskii-Moriya interactions. This stabilization mechanism potentially opens the door towards BP-based spintronic applications. An open question, from a methodological point of view, is whether the Heisenberg (HB) model approach (atomistic model) as to be used to study such systems or if the -- computationally more efficient -- micromagnetic (MM) models can be used and still obtain robust results. We are modelling and comparing the energetics and dynamics of a stable BP obtained using both HB and MM approaches. We find that an MM description of a stable BP leads qualitatively to the same results as the HB description, and that an appropriate mesh discretization plays a more important role than the chosen model. Further, we study the dynamics by shifting the BP with an applied in-plane field and investigating the relaxation after switching the filed off abruptly. The precessional motion of coupled vortices in a BP state can be drastically reduced compared to a classical vortex, which may be also an interesting feature for fast and efficient devices. A recent study has shown that a bilayer stack hosting BPs can be used to retain information [1]. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.10091v1-abstract-full').style.display = 'none'; document.getElementById('2303.10091v1-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> 17 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 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/2303.07767">arXiv:2303.07767</a> <span> [<a href="https://arxiv.org/pdf/2303.07767">pdf</a>, <a href="https://arxiv.org/format/2303.07767">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.107.245147">10.1103/PhysRevB.107.245147 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Pressure study on the interplay between magnetic order and valence-change crossover in EuPd$_2$(Si$_{1-x}$Ge$_x$)$_2$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Wolf%2C+B">Bernd Wolf</a>, <a href="/search/cond-mat?searchtype=author&query=Lundbeck%2C+T">Theresa Lundbeck</a>, <a href="/search/cond-mat?searchtype=author&query=Zimmermann%2C+J">Jan Zimmermann</a>, <a href="/search/cond-mat?searchtype=author&query=Peters%2C+M">Marius Peters</a>, <a href="/search/cond-mat?searchtype=author&query=Kliemt%2C+K">Kristin Kliemt</a>, <a href="/search/cond-mat?searchtype=author&query=Krellner%2C+C">Cornelius Krellner</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</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="2303.07767v2-abstract-short" style="display: inline;"> We present results of the magnetic susceptibility on high-quality single crystals of EuPd$_2$(Si$_{1-x}$Ge$_x$)$_2$ for Ge concentrations 0 $\leq x \leq$ 0.105 performed under varying hydrostatic (He-gas) pressure 0 $\leq p \leq$ 0.5 GPa. The work extends on recent studies at ambient pressure demonstrating the drastic change in the magnetic response from valence-change-crossover behavior for $x$ =… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.07767v2-abstract-full').style.display = 'inline'; document.getElementById('2303.07767v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.07767v2-abstract-full" style="display: none;"> We present results of the magnetic susceptibility on high-quality single crystals of EuPd$_2$(Si$_{1-x}$Ge$_x$)$_2$ for Ge concentrations 0 $\leq x \leq$ 0.105 performed under varying hydrostatic (He-gas) pressure 0 $\leq p \leq$ 0.5 GPa. The work extends on recent studies at ambient pressure demonstrating the drastic change in the magnetic response from valence-change-crossover behavior for $x$ = 0 and 0.058, to long-range antiferromagnetic (afm) order below $T_{\text{N}}$ = 47 K for $x$ = 0.105. The valence-change-crossover temperature $T'_{\text{V}}$ shows an extraordinarily strong pressure dependence of d$T'_{\text{V}}$/d$p$ = +(80 $\pm$ 10) K/GPa. In contrast, a very small pressure dependence of d$T_{\text{N}}$/d$p \leq$ +(1 $\pm$ 0.5) K/GPa is found for the afm order upon pressurizing the $x$ = 0.105 crystal from $p$ = 0 to 0.05 GPa. Remarkably, by further increasing the pressure to 0.1 GPa, a drastic change in the ground state from afm order to valence-change-crossover behavior is observed. Estimates of the electronic entropy, derived from analyzing susceptibility data at varying pressures, indicate that the boundary between afm order and valence-change crossover represents a first-order phase transition. Our results suggest a particular type of second-order critical endpoint of the first-order transition for $x$ = 0.105 at $p_{\text{cr}} \approx$ 0.06 GPa and $T_{\text{cr}} \approx$ 45 K where intriguing strong-coupling effects between fluctuating charge-, spin- and lattice degrees of freedom can be expected. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.07767v2-abstract-full').style.display = 'none'; document.getElementById('2303.07767v2-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 June, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 14 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.07472">arXiv:2303.07472</a> <span> [<a href="https://arxiv.org/pdf/2303.07472">pdf</a>, <a href="https://arxiv.org/format/2303.07472">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/PhysRevMaterials.7.064405">10.1103/PhysRevMaterials.7.064405 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> From valence fluctuations to long-range magnetic order in EuPd$_2$(Si$_{1-x}$Ge$_x$)$_2$ single crystals </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Peters%2C+M">Marius Peters</a>, <a href="/search/cond-mat?searchtype=author&query=Kliemt%2C+K">Kristin Kliemt</a>, <a href="/search/cond-mat?searchtype=author&query=Ocker%2C+M">Michelle Ocker</a>, <a href="/search/cond-mat?searchtype=author&query=Wolf%2C+B">Bernd Wolf</a>, <a href="/search/cond-mat?searchtype=author&query=Puphal%2C+P">Pascal Puphal</a>, <a href="/search/cond-mat?searchtype=author&query=Tacon%2C+M+L">Matthieu Le Tacon</a>, <a href="/search/cond-mat?searchtype=author&query=Merz%2C+M">Michael Merz</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Krellner%2C+C">Cornelius Krellner</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="2303.07472v2-abstract-short" style="display: inline;"> EuPd$_2$Si$_2$ is a valence-fluctuating system undergoing a temperature-induced valence crossover at $T'_V\approx160\,$K. We present the successful single crystal growth using the Czochralski method for the substitution series EuPd$_2$(Si$_{1-x}$Ge$_x$)$_2$, with substitution levels $x\leq 0.15$. A careful determination of the germanium content revealed that only half of the nominal concentration… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.07472v2-abstract-full').style.display = 'inline'; document.getElementById('2303.07472v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.07472v2-abstract-full" style="display: none;"> EuPd$_2$Si$_2$ is a valence-fluctuating system undergoing a temperature-induced valence crossover at $T'_V\approx160\,$K. We present the successful single crystal growth using the Czochralski method for the substitution series EuPd$_2$(Si$_{1-x}$Ge$_x$)$_2$, with substitution levels $x\leq 0.15$. A careful determination of the germanium content revealed that only half of the nominal concentration is build into the crystal structure. From thermodynamic measurements it is established that $T'_V$ is strongly suppressed for small substitution levels and antiferromagnetic order from stable divalent europium emerges for $x\gtrsim 0.10$. The valence transition is accompanied by a pronounced change of the lattice parameter $a$ of order 1.8%. In the antiferromagnetically ordered state below $T_N = 47$ K, we find sizeable magnetic anisotropy with an easy plane perpendicular to the crystallographic c direction. An entropy analysis revealed that no valence fluctuations are present for the magnetically ordered materials. Combining the obtained thermodynamic and structural data, we construct a concentration-temperature phase diagram demonstrating a rather abrupt change from a valence-fluctuating to a magnetically-ordered state in EuPd$_2$(Si$_{1-x}$Ge$_x$)$_2$. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.07472v2-abstract-full').style.display = 'none'; document.getElementById('2303.07472v2-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 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 13 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Materials 7, 064405 (2023) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2303.01784">arXiv:2303.01784</a> <span> [<a href="https://arxiv.org/pdf/2303.01784">pdf</a>, <a href="https://arxiv.org/format/2303.01784">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Physics Education">physics.ed-ph</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/10.1119/5.0149038">10.1119/5.0149038 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Numerical simulation projects in micromagnetics with Jupyter </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Lonsky%2C+M">Martin Lonsky</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Martin Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Holt%2C+S">Samuel Holt</a>, <a href="/search/cond-mat?searchtype=author&query=Pathak%2C+S+A">Swapneel Amit Pathak</a>, <a href="/search/cond-mat?searchtype=author&query=Klause%2C+R">Robin Klause</a>, <a href="/search/cond-mat?searchtype=author&query=Lo%2C+T">Tzu-Hsiang Lo</a>, <a href="/search/cond-mat?searchtype=author&query=Beg%2C+M">Marijan Beg</a>, <a href="/search/cond-mat?searchtype=author&query=Hoffmann%2C+A">Axel Hoffmann</a>, <a href="/search/cond-mat?searchtype=author&query=Fangohr%2C+H">Hans Fangohr</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="2303.01784v2-abstract-short" style="display: inline;"> We report a case study where an existing materials science course was modified to include numerical simulation projects on the micromagnetic behavior of materials. The Ubermag micromagnetic simulation software package is used in order to solve problems computationally. The simulation software is controlled through Python code in Jupyter notebooks. Our experience is that the self-paced problem-solv… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.01784v2-abstract-full').style.display = 'inline'; document.getElementById('2303.01784v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2303.01784v2-abstract-full" style="display: none;"> We report a case study where an existing materials science course was modified to include numerical simulation projects on the micromagnetic behavior of materials. The Ubermag micromagnetic simulation software package is used in order to solve problems computationally. The simulation software is controlled through Python code in Jupyter notebooks. Our experience is that the self-paced problem-solving nature of the project work can facilitate a better in-depth exploration of the course contents. We discuss which aspects of the Ubermag and the project Jupyter ecosystem have been beneficial for the students' learning experience and which could be transferred to similar teaching activities in other subject areas. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2303.01784v2-abstract-full').style.display = 'none'; document.getElementById('2303.01784v2-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> 17 July, 2024; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 3 March, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 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">Main article: 9 pages; supplementary material: 24 pages. Accepted for publication in American Journal of Physics</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2302.13774">arXiv:2302.13774</a> <span> [<a href="https://arxiv.org/pdf/2302.13774">pdf</a>, <a href="https://arxiv.org/format/2302.13774">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.107.235133">10.1103/PhysRevB.107.235133 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Field-induced effects in the spin liquid candidate PbCuTe$_{2}$O$_{6}$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Eibisch%2C+P">Paul Eibisch</a>, <a href="/search/cond-mat?searchtype=author&query=Thurn%2C+C">Christian Thurn</a>, <a href="/search/cond-mat?searchtype=author&query=Ata%2C+A">Arif Ata</a>, <a href="/search/cond-mat?searchtype=author&query=Tutsch%2C+U">Ulrich Tutsch</a>, <a href="/search/cond-mat?searchtype=author&query=Saito%2C+Y">Yohei Saito</a>, <a href="/search/cond-mat?searchtype=author&query=Hartmann%2C+S">Steffi Hartmann</a>, <a href="/search/cond-mat?searchtype=author&query=Wolf%2C+B">Bernd Wolf</a>, <a href="/search/cond-mat?searchtype=author&query=Hanna%2C+A+R+N">Abanoub R. N. Hanna</a>, <a href="/search/cond-mat?searchtype=author&query=Islam%2C+A+T+M+N">A. T. M. Nazmul Islam</a>, <a href="/search/cond-mat?searchtype=author&query=Chillal%2C+S">Shravani Chillal</a>, <a href="/search/cond-mat?searchtype=author&query=Lake%2C+B">Bella Lake</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</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="2302.13774v2-abstract-short" style="display: inline;"> PbCuTe$_2$O$_6$ is considered as one of the rare candidate materials for a three-dimensional quantum spin liquid (QSL). This assessment was based on the results of various magnetic experiments, performed mainly on polycrystalline material. More recent measurements on single crystals revealed an even more exotic behavior, yielding ferroelectric order below $T_{\text{FE}}\approx 1\,\text{K}$, accomp… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.13774v2-abstract-full').style.display = 'inline'; document.getElementById('2302.13774v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.13774v2-abstract-full" style="display: none;"> PbCuTe$_2$O$_6$ is considered as one of the rare candidate materials for a three-dimensional quantum spin liquid (QSL). This assessment was based on the results of various magnetic experiments, performed mainly on polycrystalline material. More recent measurements on single crystals revealed an even more exotic behavior, yielding ferroelectric order below $T_{\text{FE}}\approx 1\,\text{K}$, accompanied by distinct lattice distortions, and a somewhat modified magnetic response which is still consistent with a QSL. Here we report on low-temperature measurements of various thermodynamic, magnetic and dielectric properties of single crystalline PbCuTe$_2$O$_6$ in magnetic fields $B\leq 14.5\,\text{T}$. The combination of these various probes allows us to construct a detailed $B$-$T$ phase diagram including a ferroelectric phase for $B \leq$ $8\,\text{T}$ and a $B$-induced magnetic phase at $B \geq$ $11\,\text{T}$. These phases are preceded by or coincide with a structural transition from a cubic high-temperature phase into a distorted non-cubic low-temperature state. The phase diagram discloses two quantum critical points (QCPs) in the accessible field range, a ferroelectric QCP at $B_{c1}$ = $7.9\,\text{T}$ and a magnetic QCP at $B_{c2}$ = $11\,\text{T}$. Field-induced lattice distortions, observed in the state at $T>$ $1\,\text{K}$ and which are assigned to the effect of spin-orbit interaction of the Cu$^{2+}$-ions, are considered as the key mechanism by which the magnetic field couples to the dielectric degrees of freedom in this material. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.13774v2-abstract-full').style.display = 'none'; document.getElementById('2302.13774v2-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> 9 May, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 27 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2302.04483">arXiv:2302.04483</a> <span> [<a href="https://arxiv.org/pdf/2302.04483">pdf</a>, <a href="https://arxiv.org/ps/2302.04483">ps</a>, <a href="https://arxiv.org/format/2302.04483">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</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.macromol.1c00718">10.1021/acs.macromol.1c00718 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> A simple and general approach for reversible condensation polymerization with cyclization </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Kumar%2C+K+S">Kiran Suresh Kumar</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="2302.04483v1-abstract-short" style="display: inline;"> We develop a simple recursive approach to treat reversible condensation polymerization with cyclization. Based upon a minimum set of balance equations, the law of mass action, Gaussian chain statistics, and the assumption of independent reactions, we derive exact analytical solutions for systems without cyclization, for systems containing only smallest loops, or systems that exclusively form loops… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.04483v1-abstract-full').style.display = 'inline'; document.getElementById('2302.04483v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.04483v1-abstract-full" style="display: none;"> We develop a simple recursive approach to treat reversible condensation polymerization with cyclization. Based upon a minimum set of balance equations, the law of mass action, Gaussian chain statistics, and the assumption of independent reactions, we derive exact analytical solutions for systems without cyclization, for systems containing only smallest loops, or systems that exclusively form loops. Exact numerical solutions are computed for the general case of a homopolymerization of flexible precursor polymers. All solutions were tested with Monte-Carlo simulations. A generalization for good solvent is discussed and it is shown that this generalization agrees with preceding work in the limit of low and high polymer volume fractions. The new aspect of our approach is its flexibility that allows for a rather simple generalization to more complex situations. These include different kinds of reversible linear polymerization, non-linear polymerization, first shell substitution effect, semiflexibility, or a low molecular weight cut-off for cyclization. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.04483v1-abstract-full').style.display = 'none'; document.getElementById('2302.04483v1-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> 9 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Macromolecules 54, 2021, 7021 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2302.04082">arXiv:2302.04082</a> <span> [<a href="https://arxiv.org/pdf/2302.04082">pdf</a>, <a href="https://arxiv.org/ps/2302.04082">ps</a>, <a href="https://arxiv.org/format/2302.04082">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</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.macromol.1c00720">10.1021/acs.macromol.1c00720 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Reversible stepwise condensation polymerization with cyclization: strictly alternating co-polymerization and homopolymerization based upon two orthogonal reactions </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Kumar%2C+K+S">Kiran Suresh Kumar</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="2302.04082v1-abstract-short" style="display: inline;"> In a preceding work [M. Lang, K. Kumar, A simple and general approach for reversible condensation polymerization with cyclization, Macromolecules 54 (2021) 7021], we have introduced a simple recursive scheme that allows to treat stepwise linear reversible polymerizations of any kind with cyclization. This approach is used to discuss the polymerization of linear Gaussian strands (LGS) with two diff… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.04082v1-abstract-full').style.display = 'inline'; document.getElementById('2302.04082v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.04082v1-abstract-full" style="display: none;"> In a preceding work [M. Lang, K. Kumar, A simple and general approach for reversible condensation polymerization with cyclization, Macromolecules 54 (2021) 7021], we have introduced a simple recursive scheme that allows to treat stepwise linear reversible polymerizations of any kind with cyclization. This approach is used to discuss the polymerization of linear Gaussian strands (LGS) with two different reactive groups $A$ and $B$ on either chain end that participate in two orthogonal reactions and the strictly alternating copolymerization of LGS that carry $A$ reactive groups with LGS equipped with type $B$ reactive groups. The former of these cases has not been discussed theoretically in literature, the latter only regarding some special cases. We provide either analytical expressions or exact numerical solutions for the general cases with and without cyclization. Weight distributions, averages, polydispersity, and the weight fractions of cyclic and linear species are computed. All numerical solutions were tested by Monte-Carlo simulations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.04082v1-abstract-full').style.display = 'none'; document.getElementById('2302.04082v1-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> 8 February, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2023. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Macromolecules 54, 2021, 7036 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2210.12227">arXiv:2210.12227</a> <span> [<a href="https://arxiv.org/pdf/2210.12227">pdf</a>, <a href="https://arxiv.org/format/2210.12227">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"> From magnetic order to valence-change crossover in EuPd$_2$(Si$_{1-x}$Ge$_x$)$_2$ using He-gas pressure </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Wolf%2C+B">Bernd Wolf</a>, <a href="/search/cond-mat?searchtype=author&query=Spathelf%2C+F">Felix Spathelf</a>, <a href="/search/cond-mat?searchtype=author&query=Zimmermann%2C+J">Jan Zimmermann</a>, <a href="/search/cond-mat?searchtype=author&query=Lundbeck%2C+T">Theresa Lundbeck</a>, <a href="/search/cond-mat?searchtype=author&query=Kliemt%2C+K">Kristin Kliemt</a>, <a href="/search/cond-mat?searchtype=author&query=Krellner%2C+C">Cornelius Krellner</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</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="2210.12227v1-abstract-short" style="display: inline;"> We present results of magnetic susceptibility and thermal expansion measurements performed on high-quality single crystals of EuPd$_2$(Si$_{1-x}$Ge$_x$)$_2$ for 0 $\leq$ x $\leq$ 0.2 and temperatures 2 K $\leq T \leq$ 300 K. Data were taken at ambient pressure and finite He-gas pressure $p$ $\leq$ 0.5 GPa. For x = 0 and ambient pressure we observe a pronounced valence-change crossover centred arou… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.12227v1-abstract-full').style.display = 'inline'; document.getElementById('2210.12227v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2210.12227v1-abstract-full" style="display: none;"> We present results of magnetic susceptibility and thermal expansion measurements performed on high-quality single crystals of EuPd$_2$(Si$_{1-x}$Ge$_x$)$_2$ for 0 $\leq$ x $\leq$ 0.2 and temperatures 2 K $\leq T \leq$ 300 K. Data were taken at ambient pressure and finite He-gas pressure $p$ $\leq$ 0.5 GPa. For x = 0 and ambient pressure we observe a pronounced valence-change crossover centred around $T'_V$ $\approx$ 160 K with a non-magnetic ground state. This valence-change crossover is characterized by an extraordinarily strong pressure dependence of d$T'_V$ /d$p$ = (80 $\pm 10)$ K/GPa. We observe a shift of $T'_V$ to lower temperatures with increasing Ge-concentration, reaching $T'_V$ $\approx$ 90 K for x = 0.1, while still showing a non-magnetic ground state. Remarkably, on further increasing x to 0.2 we find a stable Eu$^{(2+未)+}$ valence with long-range antiferromagnetic order below $T_N$ = (47.5 $\pm$ 0.1) K, reflecting a close competition between two energy scales in this system. In fact, by the application of hydrostatic pressure as small as 0.1 GPa, the ground state of this system can be changed from long-range antiferromagnetic order for $p$ $<$ 0.1 GPa to an intermediate-valence state for $p$ $\geq$ 0.1 GPa. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.12227v1-abstract-full').style.display = 'none'; document.getElementById('2210.12227v1-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 October, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 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">9 pages, 3 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/2208.05096">arXiv:2208.05096</a> <span> [<a href="https://arxiv.org/pdf/2208.05096">pdf</a>, <a href="https://arxiv.org/ps/2208.05096">ps</a>, <a href="https://arxiv.org/format/2208.05096">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"> Phonon renormalization effects accompanying the 6 K anomaly in the Quantum Spin Liquid Candidate $魏$-(BEDT-TTF)$_{2}$Cu$_{2}$(CN)$_{3}$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Matsuura%2C+M">Masato Matsuura</a>, <a href="/search/cond-mat?searchtype=author&query=Sasaki%2C+T">Takahiko Sasaki</a>, <a href="/search/cond-mat?searchtype=author&query=Naka%2C+M">Makoto Naka</a>, <a href="/search/cond-mat?searchtype=author&query=M%C3%BCller%2C+J">Jens M眉ller</a>, <a href="/search/cond-mat?searchtype=author&query=Stockert%2C+O">Oliver Stockert</a>, <a href="/search/cond-mat?searchtype=author&query=Piovano%2C+A">Andrea Piovano</a>, <a href="/search/cond-mat?searchtype=author&query=Yoneyama%2C+N">Naoki Yoneyama</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</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="2208.05096v2-abstract-short" style="display: inline;"> The low-temperature state of the quantum spin liquid candidate $魏$-(BEDT-TTF)$_{2}$Cu$_{2}$(CN)$_{3}$ emerges via an anomaly at $T^{*}\sim6$ K. Although signatures of this anomaly have been revealed in various quantities, its origin has remained unclear. Here we report inelastic neutron scattering measurements on single crystals of $魏$-(BEDT-TTF)$_{2}$Cu$_{2}$(CN)$_{3}$, aiming at studying phonon… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.05096v2-abstract-full').style.display = 'inline'; document.getElementById('2208.05096v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2208.05096v2-abstract-full" style="display: none;"> The low-temperature state of the quantum spin liquid candidate $魏$-(BEDT-TTF)$_{2}$Cu$_{2}$(CN)$_{3}$ emerges via an anomaly at $T^{*}\sim6$ K. Although signatures of this anomaly have been revealed in various quantities, its origin has remained unclear. Here we report inelastic neutron scattering measurements on single crystals of $魏$-(BEDT-TTF)$_{2}$Cu$_{2}$(CN)$_{3}$, aiming at studying phonon renormalization effects at $T^{*}$. A drastic change was observed in the phonon damping across $T^{*}$ for a breathing mode of BEDT-TTF dimers at $E=4.7$ meV. The abrupt change in the phonon damping is attributed to a phase transition into a valence bond solid state based on an effective model describing the spin-charge coupling in this dimer-Mott system. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.05096v2-abstract-full').style.display = 'none'; document.getElementById('2208.05096v2-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 August, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 9 August, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 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">5 pages, 3 figures, supplemental materials (8 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/2206.13178">arXiv:2206.13178</a> <span> [<a href="https://arxiv.org/pdf/2206.13178">pdf</a>, <a href="https://arxiv.org/format/2206.13178">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="Other Condensed Matter">cond-mat.other</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.106.134432">10.1103/PhysRevB.106.134432 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Combined experimental and theoretical study of hydrostatic (He-gas) pressure effects in $伪$-RuCl$_3$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Wolf%2C+B">B. Wolf</a>, <a href="/search/cond-mat?searchtype=author&query=Kaib%2C+D+A+S">D. A. S. Kaib</a>, <a href="/search/cond-mat?searchtype=author&query=Razpopov%2C+A">A. Razpopov</a>, <a href="/search/cond-mat?searchtype=author&query=Biswas%2C+S">S. Biswas</a>, <a href="/search/cond-mat?searchtype=author&query=Riedl%2C+K">K. Riedl</a>, <a href="/search/cond-mat?searchtype=author&query=Winter%2C+S+M">S. M. Winter</a>, <a href="/search/cond-mat?searchtype=author&query=Valent%C3%AD%2C+R">R. Valent铆</a>, <a href="/search/cond-mat?searchtype=author&query=Saito%2C+Y">Y. Saito</a>, <a href="/search/cond-mat?searchtype=author&query=Hartmann%2C+S">S. Hartmann</a>, <a href="/search/cond-mat?searchtype=author&query=Vinokurova%2C+E">E. Vinokurova</a>, <a href="/search/cond-mat?searchtype=author&query=Doert%2C+T">T. Doert</a>, <a href="/search/cond-mat?searchtype=author&query=Isaeva%2C+A">A. Isaeva</a>, <a href="/search/cond-mat?searchtype=author&query=Bastien%2C+G">G. Bastien</a>, <a href="/search/cond-mat?searchtype=author&query=Wolter%2C+A+U+B">A. U. B. Wolter</a>, <a href="/search/cond-mat?searchtype=author&query=B%C3%BCchner%2C+B">B. B眉chner</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">M. Lang</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="2206.13178v1-abstract-short" style="display: inline;"> We report a detailed experimental and theoretical study on the effect of hydrostatic pressure on the structural and magnetic aspects of the layered honeycomb antiferromagent $伪$-RuCl$_{3}$. Magnetic susceptibility measurements performed under almost ideal hydrostatic-pressure conditions yield that the phase transition to zigzag-type antiferromagnetic order at $T_N$ = 7.3 K can be rapidly suppresse… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.13178v1-abstract-full').style.display = 'inline'; document.getElementById('2206.13178v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2206.13178v1-abstract-full" style="display: none;"> We report a detailed experimental and theoretical study on the effect of hydrostatic pressure on the structural and magnetic aspects of the layered honeycomb antiferromagent $伪$-RuCl$_{3}$. Magnetic susceptibility measurements performed under almost ideal hydrostatic-pressure conditions yield that the phase transition to zigzag-type antiferromagnetic order at $T_N$ = 7.3 K can be rapidly suppressed to about 6.1 K. A further suppression with increasing pressure is impeded due to the occurrence of a pressure-induced structural transition at $p \geq$ 104 MPa, accompanied by a strong dimerization of Ru-Ru bonds, which gives rise to a collapse of the magnetic susceptibility. Whereas the dimerization transition is strongly first order, as reflected by large discontinuous changes in $蠂$ and pronounced hysteresis effects, the magnetic transition under varying pressure and magnetic field also reveals indications for a weakly first-order transition. We assign this observation to a strong magnetoelastic coupling in this system. Measurements of $蠂$ under varying pressure in the paramagnetic regime ($T > T_N$) and before dimerization ($p <$ 100 MPa) reveal a considerable increase of $蠂$ with pressure. These experimental observations are consistent with the results of ab-initio Density Functional Theory (DFT) calculations on the pressure-dependent structure and the corresponding pressure-dependent magnetic model. Comparative susceptibility measurements on a second crystal showing two consecutive magnetic transitions instead of one, indicating the influence of stacking faults. Using different temperature-pressure protocols the effect of these stacking faults can be temporarily overcome, transforming the magnetic state from a multiple-$T_N$ into a single-$T_N$ state. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2206.13178v1-abstract-full').style.display = 'none'; document.getElementById('2206.13178v1-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 June, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2203.13689">arXiv:2203.13689</a> <span> [<a href="https://arxiv.org/pdf/2203.13689">pdf</a>, <a href="https://arxiv.org/format/2203.13689">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 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/s41598-023-33998-z">10.1038/s41598-023-33998-z <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Bloch points in nanostrips </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Martin Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Beg%2C+M">Marijan Beg</a>, <a href="/search/cond-mat?searchtype=author&query=Hovorka%2C+O">Ondrej Hovorka</a>, <a href="/search/cond-mat?searchtype=author&query=Fangohr%2C+H">Hans Fangohr</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="2203.13689v1-abstract-short" style="display: inline;"> Complex magnetic materials hosting topologically non-trivial particle-like objects such as skyrmions are under intensive research and could fundamentally change the way we store and process data. One important class of materials are helimagnetic materials with Dzyaloshinskii-Moriya interaction. Recently, it was demonstrated that nanodisks consisting of two layers with opposite chirality can host a… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.13689v1-abstract-full').style.display = 'inline'; document.getElementById('2203.13689v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2203.13689v1-abstract-full" style="display: none;"> Complex magnetic materials hosting topologically non-trivial particle-like objects such as skyrmions are under intensive research and could fundamentally change the way we store and process data. One important class of materials are helimagnetic materials with Dzyaloshinskii-Moriya interaction. Recently, it was demonstrated that nanodisks consisting of two layers with opposite chirality can host a single stable Bloch point of two different types at the interface between the layers. Using micromagnetic simulations we show that FeGe nanostrips consisting of two layers with opposite chirality can host multiple coexisting Bloch points in an arbitrary combination of the two different types. We show that the number of Bloch points that can simultaneously coexist depends on the strip geometry and the type of the individual Bloch points. Our simulation results allow us to predict strip geometries suitable for an arbitrary number of Bloch points. We show an example of an 80-Bloch-point configuration verifying the prediction. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.13689v1-abstract-full').style.display = 'none'; document.getElementById('2203.13689v1-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, 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">Comments:</span> <span class="has-text-grey-dark mathjax">12 pages, 6 figures, and 2 pages and 3 figures supplement</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2201.06350">arXiv:2201.06350</a> <span> [<a href="https://arxiv.org/pdf/2201.06350">pdf</a>, <a href="https://arxiv.org/format/2201.06350">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="Accelerator Physics">physics.acc-ph</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/10.1107/S1600577522008414">10.1107/S1600577522008414 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Megahertz-rate Ultrafast X-ray Scattering and Holographic Imaging at the European XFEL </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Hagstr%C3%B6m%2C+N+Z">Nanna Zhou Hagstr枚m</a>, <a href="/search/cond-mat?searchtype=author&query=Schneider%2C+M">Michael Schneider</a>, <a href="/search/cond-mat?searchtype=author&query=Kerber%2C+N">Nico Kerber</a>, <a href="/search/cond-mat?searchtype=author&query=Yaroslavtsev%2C+A">Alexander Yaroslavtsev</a>, <a href="/search/cond-mat?searchtype=author&query=Parra%2C+E+B">Erick Burgos Parra</a>, <a href="/search/cond-mat?searchtype=author&query=Beg%2C+M">Marijan Beg</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Martin Lang</a>, <a href="/search/cond-mat?searchtype=author&query=G%C3%BCnther%2C+C+M">Christian M. G眉nther</a>, <a href="/search/cond-mat?searchtype=author&query=Seng%2C+B">Boris Seng</a>, <a href="/search/cond-mat?searchtype=author&query=Kammerbauer%2C+F">Fabian Kammerbauer</a>, <a href="/search/cond-mat?searchtype=author&query=Popescu%2C+H">Horia Popescu</a>, <a href="/search/cond-mat?searchtype=author&query=Pancaldi%2C+M">Matteo Pancaldi</a>, <a href="/search/cond-mat?searchtype=author&query=Neeraj%2C+K">Kumar Neeraj</a>, <a href="/search/cond-mat?searchtype=author&query=Polley%2C+D">Debanjan Polley</a>, <a href="/search/cond-mat?searchtype=author&query=Jangid%2C+R">Rahul Jangid</a>, <a href="/search/cond-mat?searchtype=author&query=Hrkac%2C+S+B">Stjepan B. Hrkac</a>, <a href="/search/cond-mat?searchtype=author&query=Patel%2C+S+K+K">Sheena K. K. Patel</a>, <a href="/search/cond-mat?searchtype=author&query=Ovcharenko%2C+S">Sergei Ovcharenko</a>, <a href="/search/cond-mat?searchtype=author&query=Turenne%2C+D">Diego Turenne</a>, <a href="/search/cond-mat?searchtype=author&query=Ksenzov%2C+D">Dmitriy Ksenzov</a>, <a href="/search/cond-mat?searchtype=author&query=Boeglin%2C+C">Christine Boeglin</a>, <a href="/search/cond-mat?searchtype=author&query=Pronin%2C+I">Igor Pronin</a>, <a href="/search/cond-mat?searchtype=author&query=Baidakova%2C+M">Marina Baidakova</a>, <a href="/search/cond-mat?searchtype=author&query=Schmising%2C+C+v+K">Clemens von Korff Schmising</a>, <a href="/search/cond-mat?searchtype=author&query=Borchert%2C+M">Martin Borchert</a> , et al. (75 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="2201.06350v2-abstract-short" style="display: inline;"> The advent of X-ray free-electron lasers (XFELs) has revolutionized fundamental science, from atomic to condensed matter physics, from chemistry to biology, giving researchers access to X-rays with unprecedented brightness, coherence, and pulse duration. All XFEL facilities built until recently provided X-ray pulses at a relatively low repetition rate, with limited data statistics. Here, we presen… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2201.06350v2-abstract-full').style.display = 'inline'; document.getElementById('2201.06350v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2201.06350v2-abstract-full" style="display: none;"> The advent of X-ray free-electron lasers (XFELs) has revolutionized fundamental science, from atomic to condensed matter physics, from chemistry to biology, giving researchers access to X-rays with unprecedented brightness, coherence, and pulse duration. All XFEL facilities built until recently provided X-ray pulses at a relatively low repetition rate, with limited data statistics. Here, we present the results from the first megahertz repetition rate X-ray scattering experiments at the Spectroscopy and Coherent Scattering (SCS) instrument of the European XFEL. We illustrate the experimental capabilities that the SCS instrument offers, resulting from the operation at MHz repetition rates and the availability of the novel DSSC 2D imaging detector. Time-resolved magnetic X-ray scattering and holographic imaging experiments in solid state samples were chosen as representative, providing an ideal test-bed for operation at megahertz rates. Our results are relevant and applicable to any other non-destructive XFEL experiments in the soft X-ray range. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2201.06350v2-abstract-full').style.display = 'none'; document.getElementById('2201.06350v2-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 January, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 17 January, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 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">13 pages, 5 figures. Supplementary Information as ancillary file</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> J. Synchrotron Rad. (2022), 29 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2111.01612">arXiv:2111.01612</a> <span> [<a href="https://arxiv.org/pdf/2111.01612">pdf</a>, <a href="https://arxiv.org/format/2111.01612">other</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="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/10.2351/7.0000592">10.2351/7.0000592 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Protecting the Edge: Ultrafast Laser Modified C-shaped Glass Edges </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Flamm%2C+D">Daniel Flamm</a>, <a href="/search/cond-mat?searchtype=author&query=Kaiser%2C+M">Myriam Kaiser</a>, <a href="/search/cond-mat?searchtype=author&query=Feil%2C+M">Marvin Feil</a>, <a href="/search/cond-mat?searchtype=author&query=Kahmann%2C+M">Max Kahmann</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Kleiner%2C+J">Jonas Kleiner</a>, <a href="/search/cond-mat?searchtype=author&query=Hesse%2C+T">Tim Hesse</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="2111.01612v2-abstract-short" style="display: inline;"> A procedure and optical concept is introduced for ultrashort pulsed laser cleaving of transparent materials with tailored edges in a single pass. The procedure is based on holographically splitting a number of foci along the desired edge geometry including C-shaped edges with local 45掳 tangential angles to the surface. Single-pass, full thickness laser modifications are achieved requiring single-s… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2111.01612v2-abstract-full').style.display = 'inline'; document.getElementById('2111.01612v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2111.01612v2-abstract-full" style="display: none;"> A procedure and optical concept is introduced for ultrashort pulsed laser cleaving of transparent materials with tailored edges in a single pass. The procedure is based on holographically splitting a number of foci along the desired edge geometry including C-shaped edges with local 45掳 tangential angles to the surface. Single-pass, full thickness laser modifications are achieved requiring single-side access to the workpiece only without inclining the optical head. After having induced laser modifications with feed rates of 1 m/s actual separation is performed using a selective etching strategy. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2111.01612v2-abstract-full').style.display = 'none'; document.getElementById('2111.01612v2-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 December, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 2 November, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 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">Accepted revised article, 8 pages, 9 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> J. Laser Appl. 34, 012014 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2109.00811">arXiv:2109.00811</a> <span> [<a href="https://arxiv.org/pdf/2109.00811">pdf</a>, <a href="https://arxiv.org/format/2109.00811">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.105.L041114">10.1103/PhysRevB.105.L041114 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Involvement of structural dynamics in the charge-glass formation in molecular metals </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Thomas%2C+T">Tatjana Thomas</a>, <a href="/search/cond-mat?searchtype=author&query=Saito%2C+Y">Yohei Saito</a>, <a href="/search/cond-mat?searchtype=author&query=Agarmani%2C+Y">Yassine Agarmani</a>, <a href="/search/cond-mat?searchtype=author&query=Thyzel%2C+T">Tim Thyzel</a>, <a href="/search/cond-mat?searchtype=author&query=Hashimoto%2C+K">Kenichiro Hashimoto</a>, <a href="/search/cond-mat?searchtype=author&query=Sasaki%2C+T">Takahiko Sasaki</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</a>, <a href="/search/cond-mat?searchtype=author&query=M%C3%BCller%2C+J">Jens M眉ller</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="2109.00811v1-abstract-short" style="display: inline;"> We present a combined study of thermal expansion and resistance fluctuation spectroscopy measurements exploring the static and dynamic aspects of the charge-glass formation in the quasi-two-dimensional organic conductors $胃$-(BEDT-TTF)$_2$$MM^\prime$(SCN)$_4$ with $M$ = Cs and $M^\prime$ = Co,Zn. In these materials, the emergence of a novel charge-glass state so far has been interpreted in purely… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.00811v1-abstract-full').style.display = 'inline'; document.getElementById('2109.00811v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2109.00811v1-abstract-full" style="display: none;"> We present a combined study of thermal expansion and resistance fluctuation spectroscopy measurements exploring the static and dynamic aspects of the charge-glass formation in the quasi-two-dimensional organic conductors $胃$-(BEDT-TTF)$_2$$MM^\prime$(SCN)$_4$ with $M$ = Cs and $M^\prime$ = Co,Zn. In these materials, the emergence of a novel charge-glass state so far has been interpreted in purely electronic terms by considering the strong frustration of the Coulomb interactions on a triangular lattice. Contrary to this view, we provide comprehensive evidence for the involvement of a \textit{structural} glass-like transition at $T_{\text{g}} \sim 90-100\,$K. This glassy transition can be assigned to the freezing of structural conformations of the ethylene endgroups in the donor molecule with an activation energy of $E_{\rm{a}}\approx 0.32\,$eV, and the concomitant slowing down of the charge carrier dynamics is well described by a model of non-exponential kinetics. These findings discolse an important aspect of the phase diagram and renders the current understanding of the charge-glass state in the whole family of $胃$-(BEDT-TTF)$_2MM^\prime$(SCN)$_4$ incomplete. Our results suggest that the entanglement of slow structural and charge-cluster dynamics due to the intimate coupling of lattice and electronic degrees of freedom determine the charge-glass formation under geometric frustration. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2109.00811v1-abstract-full').style.display = 'none'; document.getElementById('2109.00811v1-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 September, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. B 105, L041114 (2022) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2108.11685">arXiv:2108.11685</a> <span> [<a href="https://arxiv.org/pdf/2108.11685">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="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/10.7566/JPSJ.90.124706">10.7566/JPSJ.90.124706 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Pressure-induced insulator-metal transition in two-dimensional Mott insulator NiPS3 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Matsuoka%2C+T">Takahiro Matsuoka</a>, <a href="/search/cond-mat?searchtype=author&query=Haglund%2C+A">Amanda Haglund</a>, <a href="/search/cond-mat?searchtype=author&query=Xue%2C+R">Rui Xue</a>, <a href="/search/cond-mat?searchtype=author&query=Smith%2C+J+S">Jesse S. Smith</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Maik Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Santos%2C+A+M+d">Antonio M. dos Santos</a>, <a href="/search/cond-mat?searchtype=author&query=Mandrus%2C+D">David Mandrus</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="2108.11685v1-abstract-short" style="display: inline;"> The pressure-induced insulator to metal transition (IMT) of layered magnetic nickel phosphorous tri-sulfide NiPS3 was studied in-situ under quasi-uniaxial conditions by means of electrical resistance (R) and X-ray diffraction (XRD) measurements. This sluggish transition is shown to occur at 35 GPa. Transport measurements show no evidence of superconductivity to the lowest measured temperature (~ 2… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.11685v1-abstract-full').style.display = 'inline'; document.getElementById('2108.11685v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2108.11685v1-abstract-full" style="display: none;"> The pressure-induced insulator to metal transition (IMT) of layered magnetic nickel phosphorous tri-sulfide NiPS3 was studied in-situ under quasi-uniaxial conditions by means of electrical resistance (R) and X-ray diffraction (XRD) measurements. This sluggish transition is shown to occur at 35 GPa. Transport measurements show no evidence of superconductivity to the lowest measured temperature (~ 2 K). The structure results presented here differ from earlier in-situ work that subjected the sample to a different pressure state, suggesting that in NiPS3 the phase stability fields are highly dependent on strain. It is suggested that careful control of the strain is essential when studying the electronic and magnetic properties of layered van der Waals solids. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2108.11685v1-abstract-full').style.display = 'none'; document.getElementById('2108.11685v1-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, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2021. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2106.02130">arXiv:2106.02130</a> <span> [<a href="https://arxiv.org/pdf/2106.02130">pdf</a>, <a href="https://arxiv.org/format/2106.02130">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/PhysRevLett.127.147204">10.1103/PhysRevLett.127.147204 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Spin Vortex Crystal Order in Organic Triangular Lattice Compound </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Riedl%2C+K">Kira Riedl</a>, <a href="/search/cond-mat?searchtype=author&query=Gati%2C+E">Elena Gati</a>, <a href="/search/cond-mat?searchtype=author&query=Zielke%2C+D">David Zielke</a>, <a href="/search/cond-mat?searchtype=author&query=Hartmann%2C+S">Steffi Hartmann</a>, <a href="/search/cond-mat?searchtype=author&query=Vyaselev%2C+O+M">Oleg M. Vyaselev</a>, <a href="/search/cond-mat?searchtype=author&query=Kushch%2C+N+D">Nataliya D. Kushch</a>, <a href="/search/cond-mat?searchtype=author&query=Jeschke%2C+H+O">Harald O. Jeschke</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Valenti%2C+R">Roser Valenti</a>, <a href="/search/cond-mat?searchtype=author&query=Kartsovnik%2C+M+V">Mark V. Kartsovnik</a>, <a href="/search/cond-mat?searchtype=author&query=Winter%2C+S+M">Stephen M. Winter</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="2106.02130v1-abstract-short" style="display: inline;"> Organic salts represent an ideal experimental playground for studying the interplay between magnetic and charge degrees of freedom, which has culminated in the discovery of several spin-liquid candidates, such as $魏$-(ET)$_2$Cu$_2$(CN)$_3$ ($魏$-Cu). Recent theoretical studies indicate the possibility of chiral spin liquids stabilized by ring-exchange, but the parent states with chiral magnetic ord… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.02130v1-abstract-full').style.display = 'inline'; document.getElementById('2106.02130v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2106.02130v1-abstract-full" style="display: none;"> Organic salts represent an ideal experimental playground for studying the interplay between magnetic and charge degrees of freedom, which has culminated in the discovery of several spin-liquid candidates, such as $魏$-(ET)$_2$Cu$_2$(CN)$_3$ ($魏$-Cu). Recent theoretical studies indicate the possibility of chiral spin liquids stabilized by ring-exchange, but the parent states with chiral magnetic order have not been observed in this material family. In this work, we discuss the properties of the recently synthesized $魏$-(BETS)$_2$Mn[N(CN)$_2$]$_3$ ($魏$-Mn). Based on analysis of specific heat, magnetic torque, and NMR measurements combined with ab initio calculations, we identify a spin-vortex crystal order. These observations definitively confirm the importance of ring-exchange in these materials, and support the proposed chiral spin-liquid scenario for triangular lattice organics. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2106.02130v1-abstract-full').style.display = 'none'; document.getElementById('2106.02130v1-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, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 127, 147204 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2105.11854">arXiv:2105.11854</a> <span> [<a href="https://arxiv.org/pdf/2105.11854">pdf</a>, <a href="https://arxiv.org/ps/2105.11854">ps</a>, <a href="https://arxiv.org/format/2105.11854">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</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/10.1002/mats.201800069">10.1002/mats.201800069 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Competing exchange and irreversible reactions in a linear co-polycondensation lead to a broad composition window where tunable high molecular weight polymers can be prepared </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</a>, <a href="/search/cond-mat?searchtype=author&query=B%C3%B6hme%2C+F">Frank B枚hme</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="2105.11854v1-abstract-short" style="display: inline;"> A co-polycondensation reaction is discussed analytically and by Monte-Carlo simulations where two reactive units compete for reactions with an alternating third reactive unit, whereby irreversible reactions replace bonds which are able to undergo exchange reactions. The resulting number average molar mass, $M_{\text{n}}$, exhibits only one distinct peak at the stoichiometric condition of both comp… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.11854v1-abstract-full').style.display = 'inline'; document.getElementById('2105.11854v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.11854v1-abstract-full" style="display: none;"> A co-polycondensation reaction is discussed analytically and by Monte-Carlo simulations where two reactive units compete for reactions with an alternating third reactive unit, whereby irreversible reactions replace bonds which are able to undergo exchange reactions. The resulting number average molar mass, $M_{\text{n}}$, exhibits only one distinct peak at the stoichiometric condition of both competitors with the alternating partner. The weight average molar mass, $M_{\text{w}}$, reaches an additional second peak at the stoichiometric condition between the dominating competitor and the alternating partner. Both peaks of $M_{\text{w}}$ surround a range of compositions where a rather high and approximately constant $M_{\text{w}}$ is obtained. The degree of polymerization of the dominating and alternating reaction partners is rather insensitive towards composition fluctuations if the reaction mixture remains within this composition window. This promotes high molecular weight species and more homogeneous weight distributions at incomplete mixing conditions. An ideal reference case (identical reaction rates for all reactions) is solved analytically to describe these reactions. The position of the stable composition window and the average molar masses inside this window can be tuned by choosing appropriate precursor molecules, reaction mixtures or post-tuning steps at later times. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.11854v1-abstract-full').style.display = 'none'; document.getElementById('2105.11854v1-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 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">Journal ref:</span> Macromol. Theory Simul. (2019) 1800069 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2105.11843">arXiv:2105.11843</a> <span> [<a href="https://arxiv.org/pdf/2105.11843">pdf</a>, <a href="https://arxiv.org/ps/2105.11843">ps</a>, <a href="https://arxiv.org/format/2105.11843">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</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/10.1063/1.4825207">10.1063/1.4825207 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Fluctuation driven height reduction of crosslinked polymer brushes </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">M. Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Hoffmann%2C+M">M. Hoffmann</a>, <a href="/search/cond-mat?searchtype=author&query=Werner%2C+M">M. Werner</a>, <a href="/search/cond-mat?searchtype=author&query=Dockhorn%2C+R">R. Dockhorn</a>, <a href="/search/cond-mat?searchtype=author&query=Sommer%2C+J+-">J. -U. Sommer</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="2105.11843v1-abstract-short" style="display: inline;"> We study the changes in the conformations of brushes upon the addition of crosslinks between the chains using the bond fluctuation model. The Flory-Rehner model applied to uni-axially swollen networks predicts a collapse for large degrees of crosslinking $q$ proportional to $q^{-1/3}$ in disagreement with our simulation data. We show that the height reduction of the brushes is driven by monomer fl… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.11843v1-abstract-full').style.display = 'inline'; document.getElementById('2105.11843v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.11843v1-abstract-full" style="display: none;"> We study the changes in the conformations of brushes upon the addition of crosslinks between the chains using the bond fluctuation model. The Flory-Rehner model applied to uni-axially swollen networks predicts a collapse for large degrees of crosslinking $q$ proportional to $q^{-1/3}$ in disagreement with our simulation data. We show that the height reduction of the brushes is driven by monomer fluctuations in direction perpendicular to the grafting plane and not due to network elasticity. We observe that the impact of crosslinking is different for reactions between monomers of the same or on different chains. If the length reduction of the effective chain length due to both types of reactions is accounted for in a function $尾(q)$, the height of the brush can be derived from a Flory approach for the equilibrium brush height leading to $H(q)\approx H_{b}尾(q)^{1/3}$, whereby $H_{b}$ denotes the height of the non-crosslinked brush. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.11843v1-abstract-full').style.display = 'none'; document.getElementById('2105.11843v1-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 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">Journal ref:</span> J. Chem. Phys. 139, 164903 (2013) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2105.11835">arXiv:2105.11835</a> <span> [<a href="https://arxiv.org/pdf/2105.11835">pdf</a>, <a href="https://arxiv.org/ps/2105.11835">ps</a>, <a href="https://arxiv.org/format/2105.11835">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Chemical Physics">physics.chem-ph</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/10.1063/1.4894503">10.1063/1.4894503 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Excluded volume effects in polymer brushes at moderate chain stretching </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Romeis%2C+D">Dirk Romeis</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</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="2105.11835v1-abstract-short" style="display: inline;"> We develop a strong stretching approximation for a polymer brush made of self-avoiding polymer chains. The density profile of the brush and the distribution of the end monomer positions in stretching direction are computed and compared with simulation data. We find that our approach leads to a clearly better approximation as compared to previous approaches based upon Gaussian elasticity at low gra… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.11835v1-abstract-full').style.display = 'inline'; document.getElementById('2105.11835v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.11835v1-abstract-full" style="display: none;"> We develop a strong stretching approximation for a polymer brush made of self-avoiding polymer chains. The density profile of the brush and the distribution of the end monomer positions in stretching direction are computed and compared with simulation data. We find that our approach leads to a clearly better approximation as compared to previous approaches based upon Gaussian elasticity at low grafting densities (moderate chain stretching), for which corrections due to finite extensibility can be ignored. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.11835v1-abstract-full').style.display = 'none'; document.getElementById('2105.11835v1-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 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">Journal ref:</span> J. Chem. Phys. 141, 104902 (2014) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2105.11819">arXiv:2105.11819</a> <span> [<a href="https://arxiv.org/pdf/2105.11819">pdf</a>, <a href="https://arxiv.org/ps/2105.11819">ps</a>, <a href="https://arxiv.org/format/2105.11819">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Chemical Physics">physics.chem-ph</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/10.1063/1.4933228">10.1063/1.4933228 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Formation and Structure of Olympic Gels </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Fischer%2C+J">Jakob Fischer</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Sommer%2C+J">Jens-Uwe Sommer</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="2105.11819v1-abstract-short" style="display: inline;"> Different methods for creating Olympic gels are analyzed using computer simulations. First ideal reference samples are obtained from freely interpenetrating semi-dilute solutions and melts of cyclic polymers. The distribution of pairwise concatenations per cyclic molecule is given by a Poisson-distribution and can be used to describe the elastic structure of the gels. Several batches of linear cha… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.11819v1-abstract-full').style.display = 'inline'; document.getElementById('2105.11819v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.11819v1-abstract-full" style="display: none;"> Different methods for creating Olympic gels are analyzed using computer simulations. First ideal reference samples are obtained from freely interpenetrating semi-dilute solutions and melts of cyclic polymers. The distribution of pairwise concatenations per cyclic molecule is given by a Poisson-distribution and can be used to describe the elastic structure of the gels. Several batches of linear chains decorated with different selectively binding groups at their ends are mixed in the "DNA Origami" technique and network formation is realized. While the formation of cyclic molecules follows mean field predictions below overlap of the precursor molecules, an enhanced ring formation above overlap is found that is not explained by mean field arguments. The "progressive construction" method allows to create Olympic gels with a single reaction step from a concentrated mixture of large compressed rings with a low weight fraction short chains that are below overlap concentration. This method, however, is limited by the difficulty to obtain a sufficiently high degree of polymerization of the large rings. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.11819v1-abstract-full').style.display = 'none'; document.getElementById('2105.11819v1-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 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">Journal ref:</span> J. Chem. Phys. 143, 243114 (2015) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2105.08355">arXiv:2105.08355</a> <span> [<a href="https://arxiv.org/pdf/2105.08355">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Computational Physics">physics.comp-ph</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/10.1109/TMAG.2021.3078896">10.1109/TMAG.2021.3078896 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Ubermag: Towards more effective micromagnetic workflows </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Beg%2C+M">Marijan Beg</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Martin Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Fangohr%2C+H">Hans Fangohr</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="2105.08355v1-abstract-short" style="display: inline;"> Computational micromagnetics has become an essential tool in academia and industry to support fundamental research and the design and development of devices. Consequently, computational micromagnetics is widely used in the community, and the fraction of time researchers spend performing computational studies is growing. We focus on reducing this time by improving the interface between the numerica… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.08355v1-abstract-full').style.display = 'inline'; document.getElementById('2105.08355v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2105.08355v1-abstract-full" style="display: none;"> Computational micromagnetics has become an essential tool in academia and industry to support fundamental research and the design and development of devices. Consequently, computational micromagnetics is widely used in the community, and the fraction of time researchers spend performing computational studies is growing. We focus on reducing this time by improving the interface between the numerical simulation and the researcher. We have designed and developed a human-centred research environment called Ubermag. With Ubermag, scientists can control an existing micromagnetic simulation package, such as OOMMF, from Jupyter notebooks. The complete simulation workflow, including definition, execution, and data analysis of simulation runs, can be performed within the same notebook environment. Numerical libraries, co-developed by the computational and data science community, can immediately be used for micromagnetic data analysis within this Python-based environment. By design, it is possible to extend Ubermag to drive other micromagnetic packages from the same environment. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2105.08355v1-abstract-full').style.display = 'none'; document.getElementById('2105.08355v1-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 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">5 pages, 2 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/2104.05264">arXiv:2104.05264</a> <span> [<a href="https://arxiv.org/pdf/2104.05264">pdf</a>, <a href="https://arxiv.org/ps/2104.05264">ps</a>, <a href="https://arxiv.org/format/2104.05264">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Chemical Physics">physics.chem-ph</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.macromol.6b00761">10.1021/acs.macromol.6b00761 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Arm retraction dynamics in dense polymer brushes </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Werner%2C+M">Marco Werner</a>, <a href="/search/cond-mat?searchtype=author&query=Dockhorn%2C+R">Ron Dockhorn</a>, <a href="/search/cond-mat?searchtype=author&query=Kreer%2C+T">Torsten Kreer</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="2104.05264v1-abstract-short" style="display: inline;"> Large scale Monte Carlo simulations of dense layers of grafted polymer chains in good solvent conditions are used to explore the relaxation of a polymer brush. Monomer displacements are analyzed for the directions parallel and perpendicular to the grafting plane. Auto-correlation functions of individual segments or chain sections are monitored as function of time. We demonstrate that the terminal… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.05264v1-abstract-full').style.display = 'inline'; document.getElementById('2104.05264v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2104.05264v1-abstract-full" style="display: none;"> Large scale Monte Carlo simulations of dense layers of grafted polymer chains in good solvent conditions are used to explore the relaxation of a polymer brush. Monomer displacements are analyzed for the directions parallel and perpendicular to the grafting plane. Auto-correlation functions of individual segments or chain sections are monitored as function of time. We demonstrate that the terminal relaxation time $蟿$ of grafted layers well in the brush regime grows exponentially with degree of polymerization $N$ of the chains, $蟿\propto N^{3}\exp(N/N_{e})$, with $N_{e}$ the entanglement degree of polymerization in the brush. One specific feature of entangled polymer brushes is that the late time relaxation of the perpendicular component coincides for all segments. We use this observation to extract the terminal relaxation time of an entangled brush. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.05264v1-abstract-full').style.display = 'none'; document.getElementById('2104.05264v1-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 April, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Macromolecules 49 (2016) 5190-5201 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2104.05257">arXiv:2104.05257</a> <span> [<a href="https://arxiv.org/pdf/2104.05257">pdf</a>, <a href="https://arxiv.org/ps/2104.05257">ps</a>, <a href="https://arxiv.org/format/2104.05257">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Chemical Physics">physics.chem-ph</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.macromol.9b02217">10.1021/acs.macromol.9b02217 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> An Analysis of the Gel Point of Polymer Model Networks by Computer Simulations </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</a>, <a href="/search/cond-mat?searchtype=author&query=M%C3%BCller%2C+T">Toni M眉ller</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="2104.05257v1-abstract-short" style="display: inline;"> The gel point of end-linked model networks is determined from computer simulation data. It is shown that the difference between the true gel point conversion, $p_{\text{c}}$, and the ideal mean field prediction for the gel point, $p_{\text{c,id}}$, is a function of the average number of cross-links per pervaded volume of a network strand, $P$, and thus, contains an explicit dependence on junction… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.05257v1-abstract-full').style.display = 'inline'; document.getElementById('2104.05257v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2104.05257v1-abstract-full" style="display: none;"> The gel point of end-linked model networks is determined from computer simulation data. It is shown that the difference between the true gel point conversion, $p_{\text{c}}$, and the ideal mean field prediction for the gel point, $p_{\text{c,id}}$, is a function of the average number of cross-links per pervaded volume of a network strand, $P$, and thus, contains an explicit dependence on junction functionality $f$. On the contrary, the amount of intra-molecular reactions at the gel point is independent of $f$ in a first approximation and exhibits a different power law dependence on the overlap number of elastic strands as compared to the gel point delay $p_{\text{c}}-p_{\text{c,id}}$. Therefore, $p_{\text{c}}-p_{\text{c,id}}$ cannot be predicted from intra-molecular reactions and vice versa in contrast to a long standing proposal in literature. Instead, the main contribution to $p_{\text{c}}-p_{\text{c,id}}$ for $P>1$ arises from the extra bonds (XB) needed to bridge the gaps between giant molecules separated in space and scales roughly $\propto\left(P-1\right)^{-1/2}$. Further corrections to scaling are due to non-ideal reaction kinetics, composition fluctuations, and incompletely screened excluded volume, which are discussed briefly. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.05257v1-abstract-full').style.display = 'none'; document.getElementById('2104.05257v1-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 April, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> acromolecules 53 (2020) 498-512 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2104.05251">arXiv:2104.05251</a> <span> [<a href="https://arxiv.org/pdf/2104.05251">pdf</a>, <a href="https://arxiv.org/ps/2104.05251">ps</a>, <a href="https://arxiv.org/format/2104.05251">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</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/ma300942a">10.1021/ma300942a <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Effect of Topology on the Conformations of Ring Polymers </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Fischer%2C+J">Jakob Fischer</a>, <a href="/search/cond-mat?searchtype=author&query=Sommer%2C+J">Jens-Uwe Sommer</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="2104.05251v1-abstract-short" style="display: inline;"> The bond fluctuation method is used to simulate both non-concatenated entangled and interpenetrating melts of ring polymers. We find that the swelling of interpenetrating rings upon dilution follows the same laws as for linear chains. Knotting and linking probabilities of ring polymers in semi-dilute solution are analyzed using the HOMFLY polynomial. We find an exponential decay of the knotting pr… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.05251v1-abstract-full').style.display = 'inline'; document.getElementById('2104.05251v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2104.05251v1-abstract-full" style="display: none;"> The bond fluctuation method is used to simulate both non-concatenated entangled and interpenetrating melts of ring polymers. We find that the swelling of interpenetrating rings upon dilution follows the same laws as for linear chains. Knotting and linking probabilities of ring polymers in semi-dilute solution are analyzed using the HOMFLY polynomial. We find an exponential decay of the knotting probability of rings. The correlation length of the semi-dilute solution can be used to superimpose knotting data at different concentrations. A power law dependence $f_{n}\sim蠁R^{2}\sim蠁^{0.77}N$ for the average number $f_{n}$ of linked rings per ring at concentrations larger than the overlap volume fraction of rings $蠁^{*}$ is determined from the simulation data. The fraction of non-concatenated rings displays an exponential decay $P_{OO}\sim\exp(-f_{n})$, which indicates $f_{n}$ to provide the entropic effort for not forming concatenated conformations. Based upon this results we find four different regimes for the conformations of rings in melts that are separated by a critical lengths $N_{OO}$, $N_{C}$ and $N^{*}$. $N_{OO}$ describes the onset of the effect of non-concatenation below which topological effects are not important, $N_{C}$ is the cross-over between weak and strong compression of rings, and $N^{*}$ is defined by the cross-over from a non-concatenation contribution $f_{n}\sim蠁R^{2}$ to an overlap dominated concatenation contribution $f_{n}\sim蠁N^{1/2}$ at $N>N^{*}$. For $N_{OO}<N<N_{C}$, the scaling of ring sizes $R\sim N^{2/5}$ results from balancing non-concatenation with weak compression of rings. For $N_{C}<N<N^{*}$, non-concatenation and strong compression imply $R\sim N^{3/8}$. Our simulation data for non-interpenetrating rings up to $N=1024$ are in good agreement with the prediction for weakly compressed rings. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.05251v1-abstract-full').style.display = 'none'; document.getElementById('2104.05251v1-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 April, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Macromolecules 45 (2012) 7642-7648 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2104.05242">arXiv:2104.05242</a> <span> [<a href="https://arxiv.org/pdf/2104.05242">pdf</a>, <a href="https://arxiv.org/ps/2104.05242">ps</a>, <a href="https://arxiv.org/format/2104.05242">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Chemical Physics">physics.chem-ph</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/acsmacrolett.8b00020">10.1021/acsmacrolett.8b00020 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Elasticity of Phantom Model Networks with Cyclic Defects </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</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="2104.05242v1-abstract-short" style="display: inline;"> The impact of finite cycles on the phantom modulus in an otherwise perfect network is computed exactly. It is shown that pending cycles reduce the phantom modulus of the network by $kT/V$ independent of junction functionality. The correction for nonpending cycles is larger than estimated previously within this particular approximation of the surrounding network structure. It is discussed that loop… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.05242v1-abstract-full').style.display = 'inline'; document.getElementById('2104.05242v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2104.05242v1-abstract-full" style="display: none;"> The impact of finite cycles on the phantom modulus in an otherwise perfect network is computed exactly. It is shown that pending cycles reduce the phantom modulus of the network by $kT/V$ independent of junction functionality. The correction for nonpending cycles is larger than estimated previously within this particular approximation of the surrounding network structure. It is discussed that loop formation inevitably leads to streched chain conformations, if the loops are built step by step as part of the network structure. All network loops tend to contract simultaneously to optimize conformations, which leads to an increasing stretch of chains in larger loops that can be observed in computer simulations. Possible other corrections to the phantom modulus that were left aside in previous work are discussed briefly. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.05242v1-abstract-full').style.display = 'none'; document.getElementById('2104.05242v1-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 April, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> ACS Macro Letters 7 (2018) 536-539 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2103.17175">arXiv:2103.17175</a> <span> [<a href="https://arxiv.org/pdf/2103.17175">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/10.1038/s41535-021-00395-6">10.1038/s41535-021-00395-6 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Spin liquid and ferroelectricity close to a quantum critical point in PbCuTe$_2$O$_6$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Thurn%2C+C">Christian Thurn</a>, <a href="/search/cond-mat?searchtype=author&query=Eibisch%2C+P">Paul Eibisch</a>, <a href="/search/cond-mat?searchtype=author&query=Ata%2C+A">Arif Ata</a>, <a href="/search/cond-mat?searchtype=author&query=Winkler%2C+M">Maximilian Winkler</a>, <a href="/search/cond-mat?searchtype=author&query=Lunkenheimer%2C+P">Peter Lunkenheimer</a>, <a href="/search/cond-mat?searchtype=author&query=K%C3%A9zsm%C3%A1rki%2C+I">Istv谩n K茅zsm谩rki</a>, <a href="/search/cond-mat?searchtype=author&query=Tutsch%2C+U">Ulrich Tutsch</a>, <a href="/search/cond-mat?searchtype=author&query=Saito%2C+Y">Yohei Saito</a>, <a href="/search/cond-mat?searchtype=author&query=Hartmann%2C+S">Steffi Hartmann</a>, <a href="/search/cond-mat?searchtype=author&query=Zimmermann%2C+J">Jan Zimmermann</a>, <a href="/search/cond-mat?searchtype=author&query=Hanna%2C+A+R+N">Abanoub R. N. Hanna</a>, <a href="/search/cond-mat?searchtype=author&query=Islam%2C+A+T+M+N">A. T. M. Nazmul Islam</a>, <a href="/search/cond-mat?searchtype=author&query=Chillal%2C+S">Shravani Chillal</a>, <a href="/search/cond-mat?searchtype=author&query=Lake%2C+B">Bella Lake</a>, <a href="/search/cond-mat?searchtype=author&query=Wolf%2C+B">Bernd Wolf</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</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="2103.17175v2-abstract-short" style="display: inline;"> Geometrical frustration among interacting spins combined with strong quantum fluctuations destabilize long-range magnetic order in favour of more exotic states such as spin liquids. By following this guiding principle, a number of spin liquid candidate systems were identified in quasi-two-dimensional (quasi-2D) systems. For 3D, however, the situation is less favourable as quantum fluctuations are… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2103.17175v2-abstract-full').style.display = 'inline'; document.getElementById('2103.17175v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2103.17175v2-abstract-full" style="display: none;"> Geometrical frustration among interacting spins combined with strong quantum fluctuations destabilize long-range magnetic order in favour of more exotic states such as spin liquids. By following this guiding principle, a number of spin liquid candidate systems were identified in quasi-two-dimensional (quasi-2D) systems. For 3D, however, the situation is less favourable as quantum fluctuations are reduced and competing states become more relevant. Here we report a comprehensive study of thermodynamic, magnetic and dielectric properties on single crystalline and pressed-powder samples of PbCuTe$_2$O$_6$, a candidate material for a 3D frustrated quantum spin liquid featuring a hyperkagome lattice. Whereas the low-temperature properties of the powder samples are consistent with the recently proposed quantum spin liquid state, an even more exotic behaviour is revealed for the single crystals. These crystals show ferroelectric order at $T_{\text{FE}} \approx 1\,\text{K}$, accompanied by strong lattice distortions, and a modified magnetic response -- still consistent with a quantum spin liquid -- but with clear indications for quantum critical behaviour. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2103.17175v2-abstract-full').style.display = 'none'; document.getElementById('2103.17175v2-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, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 31 March, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 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">59 pages, 15 figures, This version of the article has been accepted for publication, after peer review but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> npj Quantum Materials 6, 95 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2103.16274">arXiv:2103.16274</a> <span> [<a href="https://arxiv.org/pdf/2103.16274">pdf</a>, <a href="https://arxiv.org/ps/2103.16274">ps</a>, <a href="https://arxiv.org/format/2103.16274">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</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.112.238001">10.1103/PhysRevLett.112.238001 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The Swelling of Olympic Gels </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Fischer%2C+J">Jakob Fischer</a>, <a href="/search/cond-mat?searchtype=author&query=Werner%2C+M">Marco Werner</a>, <a href="/search/cond-mat?searchtype=author&query=Sommer%2C+J">Jens-Uwe Sommer</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="2103.16274v1-abstract-short" style="display: inline;"> The swelling equilibrium of Olympic gels, which are composed of entangled cyclic polymers, is studied by Monte Carlo Simulations. In contrast to chemically crosslinked polymer networks, we observe that Olympic gels made of chains with a \emph{larger} degree of polymerization, $N$, exhibit a \emph{smaller} equilibrium swelling degree, $Q\propto N^{-0.28}蠁_{0}^{-0.72}$, at the same polymer volume fr… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2103.16274v1-abstract-full').style.display = 'inline'; document.getElementById('2103.16274v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2103.16274v1-abstract-full" style="display: none;"> The swelling equilibrium of Olympic gels, which are composed of entangled cyclic polymers, is studied by Monte Carlo Simulations. In contrast to chemically crosslinked polymer networks, we observe that Olympic gels made of chains with a \emph{larger} degree of polymerization, $N$, exhibit a \emph{smaller} equilibrium swelling degree, $Q\propto N^{-0.28}蠁_{0}^{-0.72}$, at the same polymer volume fraction $蠁_{0}$ at network preparation. This observation is explained by a desinterspersion process of overlapping non-concatenated rings upon swelling. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2103.16274v1-abstract-full').style.display = 'none'; document.getElementById('2103.16274v1-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 March, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 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">arXiv admin note: substantial text overlap with arXiv:2103.15480</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 112 (2014) 238001 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2103.16268">arXiv:2103.16268</a> <span> [<a href="https://arxiv.org/pdf/2103.16268">pdf</a>, <a href="https://arxiv.org/ps/2103.16268">ps</a>, <a href="https://arxiv.org/format/2103.16268">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</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/ma300317z">10.1021/ma300317z <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Short Cyclic Structures in Polymer Model Networks: A Test of Mean Field Approximation by Monte Carlo Simulations </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Schwenke%2C+K">Konrad Schwenke</a>, <a href="/search/cond-mat?searchtype=author&query=Sommer%2C+J">Jens-Uwe Sommer</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="2103.16268v1-abstract-short" style="display: inline;"> A mean field rate theory description of the homo- and co-polymerization of $f$-functional molecules is developed, which contains the formation of short cyclic structures inside the network. The predictions of this model are compared with Monte-Carlo simulations of cross-linking of star polymers in solution. We find that homo-polymerizations are well captured by mean-field models at concentrations… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2103.16268v1-abstract-full').style.display = 'inline'; document.getElementById('2103.16268v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2103.16268v1-abstract-full" style="display: none;"> A mean field rate theory description of the homo- and co-polymerization of $f$-functional molecules is developed, which contains the formation of short cyclic structures inside the network. The predictions of this model are compared with Monte-Carlo simulations of cross-linking of star polymers in solution. We find that homo-polymerizations are well captured by mean-field models at concentrations larger than one quarter of the geometrical overlap concentration. All simulation data can be fit using a single geometric parameter for cyclization. The simulation data reveal that within the range of parameters of the present study correlations among multiply connected molecules can be neglected. Thus, mean-field treatments of homopolymerizations are reasonable approximations, if short cycles are properly addressed. Co-polymerization is considered in the case of strict A-B reactions, where all reactive groups of individual molecules are either of type A or B. For these systems we find a clear influence of the local intermixing of A and B groups for all concentrations investigated. In consequence, mean-field models are less appropriate to describe the simulation data. The lack of ring structures containing an odd number of molecules as compared to homopolymerizations at the same extent of reaction allows for the formation of stable AB networks at concentrations one order of magnitude below the geometrical overlap concentration. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2103.16268v1-abstract-full').style.display = 'none'; document.getElementById('2103.16268v1-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 March, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Macromolecules 45 (2012) 4886-4895 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2103.16259">arXiv:2103.16259</a> <span> [<a href="https://arxiv.org/pdf/2103.16259">pdf</a>, <a href="https://arxiv.org/ps/2103.16259">ps</a>, <a href="https://arxiv.org/format/2103.16259">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</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/ma202022q">10.1021/ma202022q <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> On the Structure of Star-Polymer Networks </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Schwenke%2C+K">Konrad Schwenke</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Sommer%2C+J">Jens-Uwe Sommer</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="2103.16259v1-abstract-short" style="display: inline;"> Using the bond fluctuation model we study polymer networks obtained by endlinking of symmetric 4-arm star polymers. We consider two types of systems. Solutions of one type (A) of star polymers and solution of two types (A,B) of star polymer where A-type polymers can only crosslink with B-type polymers. We find that network defects in $A$ networks are dominated by short dangling loops close to over… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2103.16259v1-abstract-full').style.display = 'inline'; document.getElementById('2103.16259v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2103.16259v1-abstract-full" style="display: none;"> Using the bond fluctuation model we study polymer networks obtained by endlinking of symmetric 4-arm star polymers. We consider two types of systems. Solutions of one type (A) of star polymers and solution of two types (A,B) of star polymer where A-type polymers can only crosslink with B-type polymers. We find that network defects in $A$ networks are dominated by short dangling loops close to overlap concentration $c^{*}$. $AB$ networks develop a more perfect network structure, since loop sizes involving an odd number of stars are impossible, and thus, the most frequent dangling loop with largest impact on the phantom modulus is absent. The analysis of the pair-correlation and scattering function reveals that there is an amorphous packing of $A$ and $B$ type stars with a homogenization of $A$ and $B$ concentrations upon cross-linking at intermediate length scales in contrast to the previously suggested crystalline like order of $A$ and $B$ components at $c^{*}$. This result is corroborated by the coincidence of the probabilities of the shortest loop structures (which is impossible upon the previously suggested packing of stars) in both types of networks. Furthermore, we derive the vector order parameters associated with the most frequent network structures based on the phantom model. In particular, for $AB$ networks we can show that there is a dominating cyclic defect with a clearly separated order parameter that could be used to analyze cyclic network defects. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2103.16259v1-abstract-full').style.display = 'none'; document.getElementById('2103.16259v1-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 March, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Macromolecules 44 (2011) 9464-9472 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2103.16243">arXiv:2103.16243</a> <span> [<a href="https://arxiv.org/pdf/2103.16243">pdf</a>, <a href="https://arxiv.org/ps/2103.16243">ps</a>, <a href="https://arxiv.org/format/2103.16243">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</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/ma402013b">10.1021/ma402013b <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Monomer Fluctuations and the Distribution of Residual Bond Orientations in Polymer Networks </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</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="2103.16243v1-abstract-short" style="display: inline;"> In the present work, four series of simulations are analyzed: entangled model networks of a) mono-disperse or b) poly-disperse weight distribution between the crosslinks, c) non-entangled phantom model networks and d) non-entangled model networks with excluded volume interactions. Previous work on the average residual bond orientations (RBO) of model networks [1] is extended to describe the distri… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2103.16243v1-abstract-full').style.display = 'inline'; document.getElementById('2103.16243v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2103.16243v1-abstract-full" style="display: none;"> In the present work, four series of simulations are analyzed: entangled model networks of a) mono-disperse or b) poly-disperse weight distribution between the crosslinks, c) non-entangled phantom model networks and d) non-entangled model networks with excluded volume interactions. Previous work on the average residual bond orientations (RBO) of model networks [1] is extended to describe the distribution of RBOs for the entangled networks of the present study. The phantom model can be used to describe the monomer fluctuations, average RBOs, and the distribution of RBOs in networks without entanglements and without excluded volume. Monomer fluctuations in networks with excluded volume but without entanglements can be described if the phantom model is corrected by the effect of the incompletely screened excluded volume. It is shown that parameters of the tube model can be determined from monomer fluctuations in polymer networks and from the RBO. A scaling of the RBO $\propto N^{-1/2}$ is observed in both mono-disperse and poly-disperse entangled networks, while for all networks without entanglements an RBO $\propto N^{-1}$ is found. The distribution of the RBO of entangled samples can be described by assuming a normal distribution of tube lengths that is broadened by local fluctuations in tube curvature. Both observables, monomer fluctuations and RBO, are in agreement with slip link or slip tube models [2] for networks and disagree with network models that do not allow a sliding motion of the monomers along a confining tube. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2103.16243v1-abstract-full').style.display = 'none'; document.getElementById('2103.16243v1-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 March, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Macromolecules 46 (2013) 9782-9797 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2103.16233">arXiv:2103.16233</a> <span> [<a href="https://arxiv.org/pdf/2103.16233">pdf</a>, <a href="https://arxiv.org/ps/2103.16233">ps</a>, <a href="https://arxiv.org/format/2103.16233">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Statistical Mechanics">cond-mat.stat-mech</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/ma301359b">10.1021/ma301359b <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Ring conformations in bidisperse blends of ring polymers </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</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="2103.16233v1-abstract-short" style="display: inline;"> The size of rings (also called cyclic polymers) in bidisperse blends of chemically identical rings is analyzed by computer simulations. Data of entangled ring blends and blends of interpenetrating rings are compared and it is shown that the compression of entangled rings can be explained by the changes in the penetrable fraction of the minimal surface bounded by the ring. Corrections for small rin… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2103.16233v1-abstract-full').style.display = 'inline'; document.getElementById('2103.16233v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2103.16233v1-abstract-full" style="display: none;"> The size of rings (also called cyclic polymers) in bidisperse blends of chemically identical rings is analyzed by computer simulations. Data of entangled ring blends and blends of interpenetrating rings are compared and it is shown that the compression of entangled rings can be explained by the changes in the penetrable fraction of the minimal surface bounded by the ring. Corrections for small rings can be approximated by a concatenation probability $1-P_{OO}$ that a ring entraps at least one other ring. Both results are in line with a previous work [1] to explain the compression of entangled rings in monodisperse melts. Bond-bond correlations in melts of interpenetrating rings lead to similar corrections for ring sizes as reported previously [2] for monodisperse linear melts. For entangled rings, bond-bond correlations show an anti-correlation peak at a curvilinear distance of about ten segments that coincides with a horizontal tangent in the normalized mean square internal distances along the ring. Both observations become independent of melt molecular weight for sufficiently large degrees of polymerization and such behavior is not found in samples with entanglements switched off. In consequence, the length scale of topological interactions (entanglement length) in a melt of entangled rings must be considered as constant in contrast to a recent proposal by Sakaue [3]. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2103.16233v1-abstract-full').style.display = 'none'; document.getElementById('2103.16233v1-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 March, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Macromolecules 46 (2013) 1158-1166 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2103.16181">arXiv:2103.16181</a> <span> [<a href="https://arxiv.org/pdf/2103.16181">pdf</a>, <a href="https://arxiv.org/ps/2103.16181">ps</a>, <a href="https://arxiv.org/format/2103.16181">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</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.macromol.9b00996">10.1021/acs.macromol.9b00996 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> On the Elasticity of Polymer Model Networks Containing Finite Loops </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</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="2103.16181v1-abstract-short" style="display: inline;"> Based upon the resistor analogy and using the ideal loop gas approximation(ILGA) it is shown that only pending loops reduce the modulus of an otherwise perfect network made of monodisperse strands and junctions of identical functionality. Thus, the cycle rank of the network with pending structures removed (cyclic and branched) is sufficient to characterize modulus, if the resistor analogy can be e… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2103.16181v1-abstract-full').style.display = 'inline'; document.getElementById('2103.16181v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2103.16181v1-abstract-full" style="display: none;"> Based upon the resistor analogy and using the ideal loop gas approximation(ILGA) it is shown that only pending loops reduce the modulus of an otherwise perfect network made of monodisperse strands and junctions of identical functionality. Thus, the cycle rank of the network with pending structures removed (cyclic and branched) is sufficient to characterize modulus, if the resistor analogy can be employed. It is further shown that it is impossible to incorporate finite cycles into a polymer network such that individual network strands are at equilibrium conformations while maintaining simultaneously a force balance at the junctions. Therefore, the resistor analogy provides only an approximation for the phantom modulus of networks containing finite loops. Improved approaches to phantom modulus can be constructed from considering a force balance at the junctions, which requires knowledge of the distribution of cross-link fluctuations in imperfect networks. Assuming loops with equilibrium conformations and a force balance at all loop junctions, a lower bound estimate for the phantom modulus, $G_{\text{ph}}\approx\left(尉-c_{\text{f}}L_{1}\right)kT/V$ is obtained within the ILGA for end-linked model networks and in the limit of $L_{1}\ll尉$. Here, $L_{1}$ is the number of primary ("pending") loops, $尉$ the cycle rank of the network, $k$ the Boltzmann constant, $V$ the volume of the sample, and $T$ the absolute temperature. $c_{\text{f}}$ is a functionality dependent coefficient that is $\approx2.56$ for junction functionality $f=3$ and $\approx3.06$ for $f=4$, while it converges quickly towards $\approx4.2$ in the limit of large $f$. Further corrections to phantom modulus beyond finite loops are addressed briefly. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2103.16181v1-abstract-full').style.display = 'none'; document.getElementById('2103.16181v1-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 March, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Macromolecules 52 (2019) 6266-6273 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2103.15480">arXiv:2103.15480</a> <span> [<a href="https://arxiv.org/pdf/2103.15480">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Computational Physics">physics.comp-ph</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/10.1002/masy.201500013">10.1002/masy.201500013 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Olympic Gels: Concatenation and Swelling </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Fischer%2C+J">Jakob Fischer</a>, <a href="/search/cond-mat?searchtype=author&query=Werner%2C+M">Marco Werner</a>, <a href="/search/cond-mat?searchtype=author&query=Sommer%2C+J">Jens-Uwe Sommer</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="2103.15480v1-abstract-short" style="display: inline;"> Concatenation and equilibrium swelling of Olympic gels, which are composed of entangled cyclic polymers, is studied by Monte Carlo Simulations. The average number of concatenated molecules per cyclic polymers, $f_n$, is found to depend on the degree of polymerization, $N$, and polymer volume fraction at network preparation, $蠁_0$, as $f_n ~ 蠁_0^{谓/(3谓-1)}N$ with scaling exponent $谓 = 0.588$. In co… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2103.15480v1-abstract-full').style.display = 'inline'; document.getElementById('2103.15480v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2103.15480v1-abstract-full" style="display: none;"> Concatenation and equilibrium swelling of Olympic gels, which are composed of entangled cyclic polymers, is studied by Monte Carlo Simulations. The average number of concatenated molecules per cyclic polymers, $f_n$, is found to depend on the degree of polymerization, $N$, and polymer volume fraction at network preparation, $蠁_0$, as $f_n ~ 蠁_0^{谓/(3谓-1)}N$ with scaling exponent $谓 = 0.588$. In contrast to chemically cross-linked polymer networks, we observe that Olympic gels made of longer cyclic chains exhibit a smaller equilibrium swelling degree, $Q ~ N^{-0.28} 蠁_0^{-0.72}$, at the same polymer volume fraction $蠁_0$. This observation is explained by a desinterspersion process of overlapping non-concatenated rings upon swelling, which is tested directly by analyzing the change in overlap of the molecules upon swelling. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2103.15480v1-abstract-full').style.display = 'none'; document.getElementById('2103.15480v1-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, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2021. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Macromolecular Symposia 358 (2015) p.140-147 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2009.09060">arXiv:2009.09060</a> <span> [<a href="https://arxiv.org/pdf/2009.09060">pdf</a>, <a href="https://arxiv.org/format/2009.09060">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Soft Condensed Matter">cond-mat.soft</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Statistical Mechanics">cond-mat.stat-mech</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Biological Physics">physics.bio-ph</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.126.208102">10.1103/PhysRevLett.126.208102 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Chemotaxis of cargo-carrying self-propelled particles </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Vuijk%2C+H+D">Hidde D. Vuijk</a>, <a href="/search/cond-mat?searchtype=author&query=Merlitz%2C+H">Holger Merlitz</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Sharma%2C+A">Abhinav Sharma</a>, <a href="/search/cond-mat?searchtype=author&query=Sommer%2C+J">Jens-Uwe Sommer</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="2009.09060v1-abstract-short" style="display: inline;"> Active particles with their characteristic feature of self-propulsion are regarded as the simplest models for motility in living systems. The accumulation of active particles in low activity regions has led to the general belief that chemotaxis requires additional features and at least a minimal ability to process information and to control motion. We show that self-propelled particles display che… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2009.09060v1-abstract-full').style.display = 'inline'; document.getElementById('2009.09060v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2009.09060v1-abstract-full" style="display: none;"> Active particles with their characteristic feature of self-propulsion are regarded as the simplest models for motility in living systems. The accumulation of active particles in low activity regions has led to the general belief that chemotaxis requires additional features and at least a minimal ability to process information and to control motion. We show that self-propelled particles display chemotaxis and move into regions of higher activity, if the particles perform work on passive objects, or cargo, to which they are bound. The origin of this cooperative chemotaxis is the exploration of the activity gradient by the active particle when bound to a load, resulting in an average excess force on the load in the direction of higher activity. Using a minimalistic theoretical model, we capture the most relevant features of these active-passive dimers and in particular we predict the crossover between anti-chemotactic and chemotactic behaviour. Moreover we show that merely connecting active particles to chains is sufficient to obtain the crossover from anti-chemotaxis to chemotaxis with increasing chain length. Such an active complex is capable of moving up a gradient of activity such as provided by a gradient of fuel and to accumulate where the fuel concentration is at its maximum. The observed transition is of significance to proto-forms of life enabling them to locate a source of nutrients even in the absence of any supporting sensomotoric apparatus. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2009.09060v1-abstract-full').style.display = 'none'; document.getElementById('2009.09060v1-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, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> September 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 126, 208102 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2007.11703">arXiv:2007.11703</a> <span> [<a href="https://arxiv.org/pdf/2007.11703">pdf</a>, <a href="https://arxiv.org/format/2007.11703">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"> Characterization of the pressure coefficient of manganin and temperature evolution of pressure in piston-cylinder cells </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Xiang%2C+L">Li Xiang</a>, <a href="/search/cond-mat?searchtype=author&query=Gati%2C+E">Elena Gati</a>, <a href="/search/cond-mat?searchtype=author&query=Bud%27ko%2C+S+L">Sergey L. Bud'ko</a>, <a href="/search/cond-mat?searchtype=author&query=Ribeiro%2C+R+A">Raquel A. Ribeiro</a>, <a href="/search/cond-mat?searchtype=author&query=Ata%2C+A">Arif Ata</a>, <a href="/search/cond-mat?searchtype=author&query=Tutsch%2C+U">Ulrich Tutsch</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Canfield%2C+P+C">Paul C. Canfield</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="2007.11703v1-abstract-short" style="display: inline;"> We report measurements of the temperature- and pressure-dependent resistance, $R(T,p)$, of a manganin manometer in a $^4$He-gas pressure setup from room temperature down to the solidification temperature of $^4$He ($T_\textrm {solid}\sim$ 50 K at 0.8 GPa) for pressures, $p$, between 0 GPa and $\sim$0.8 GPa. The same manganin wire manometer was also measured in a piston-cylinder cell from 300 K dow… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2007.11703v1-abstract-full').style.display = 'inline'; document.getElementById('2007.11703v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2007.11703v1-abstract-full" style="display: none;"> We report measurements of the temperature- and pressure-dependent resistance, $R(T,p)$, of a manganin manometer in a $^4$He-gas pressure setup from room temperature down to the solidification temperature of $^4$He ($T_\textrm {solid}\sim$ 50 K at 0.8 GPa) for pressures, $p$, between 0 GPa and $\sim$0.8 GPa. The same manganin wire manometer was also measured in a piston-cylinder cell from 300 K down to 1.8 K and for pressures between 0 GPa to $\sim$2 GPa. From these data, we infer the temperature and pressure dependence of the pressure coefficient of manganin, $伪(T,p)$, defined by the equation $R_p = (1+伪p) R_0$ where $R_0$ and $R_p$ are the resistance of manganin at ambient pressure and finite pressure, respectively. Our results indicate that upon cooling $伪$ first decreases, then goes through a broad minimum at $\sim$120 K and increases again towards lower temperatures. In addition, we find that $伪$ is almost pressure-independent for $T\gtrsim$60 K up to $p\sim$2 GPa, but shows a pronounced $p$ dependence for $T\lesssim$60K. Using this manganin manometer, we demonstrate that $p$ overall decreases with decreasing temperature in the piston-cylinder cell for the full pressure range and that the size of the pressure difference between room temperature and low temperatures ($T=1.8$ K), $螖p$, decreases with increasing pressure. We also compare the pressure values inferred from the magnanin manometer with the low-temperature pressure, determined from the superconducting transition temperature of elemental lead (Pb). As a result of these data and analysis we propose a practical algorithm to infer the evolution of pressure with temperature in a piston-cylinder cell. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2007.11703v1-abstract-full').style.display = 'none'; document.getElementById('2007.11703v1-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, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2020. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2001.03711">arXiv:2001.03711</a> <span> [<a href="https://arxiv.org/pdf/2001.03711">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/10.1016/B978-0-12-803581-8.11644-3">10.1016/B978-0-12-803581-8.11644-3 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Fundamental Phenomena and Applications of Swift Heavy Ion Irradiations </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Maik Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Djurabekova%2C+F">Flyura Djurabekova</a>, <a href="/search/cond-mat?searchtype=author&query=Medvedev%2C+N">Nikita Medvedev</a>, <a href="/search/cond-mat?searchtype=author&query=Toulemonde%2C+M">Marcel Toulemonde</a>, <a href="/search/cond-mat?searchtype=author&query=Trautmann%2C+C">Christina Trautmann</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="2001.03711v1-abstract-short" style="display: inline;"> This review concentrates on the specific properties and characteristics of damage structures generated with high-energy ions in the electronic energy loss regime. Irradiation experiments with so-called swift heavy ions (SHI) find applications in many different fields, with examples presented in ion-track nanotechnology, radiation hardness analysis of functional materials, and laboratory tests of c… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.03711v1-abstract-full').style.display = 'inline'; document.getElementById('2001.03711v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2001.03711v1-abstract-full" style="display: none;"> This review concentrates on the specific properties and characteristics of damage structures generated with high-energy ions in the electronic energy loss regime. Irradiation experiments with so-called swift heavy ions (SHI) find applications in many different fields, with examples presented in ion-track nanotechnology, radiation hardness analysis of functional materials, and laboratory tests of cosmic radiation. The basics of the SHI-solid interaction are described with special attention to processes in the electronic subsystem. The broad spectrum of damage phenomena is exemplified for various materials and material classes, along with a description of typical characterization techniques. The review also presents state-of-the-art modeling efforts that try to account for the complexity of the coupled processes of the electronic and atomic subsystems. Finally, the relevance of SHI phenomena for effects induced by fission fragments in nuclear fuels and how this knowledge can be applied to better estimate damage risks in nuclear materials is discussed. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2001.03711v1-abstract-full').style.display = 'none'; document.getElementById('2001.03711v1-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 January, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2020. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1911.02057">arXiv:1911.02057</a> <span> [<a href="https://arxiv.org/pdf/1911.02057">pdf</a>, <a href="https://arxiv.org/ps/1911.02057">ps</a>, <a href="https://arxiv.org/format/1911.02057">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.101.140401">10.1103/PhysRevB.101.140401 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Impurity Moments Conceal Low-Energy Relaxation of Quantum Spin Liquids </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Pustogow%2C+A">A. Pustogow</a>, <a href="/search/cond-mat?searchtype=author&query=Le%2C+T">T. Le</a>, <a href="/search/cond-mat?searchtype=author&query=Wang%2C+H+-">H. -H. Wang</a>, <a href="/search/cond-mat?searchtype=author&query=Luo%2C+Y">Yongkang Luo</a>, <a href="/search/cond-mat?searchtype=author&query=Gati%2C+E">E. Gati</a>, <a href="/search/cond-mat?searchtype=author&query=Schubert%2C+H">H. Schubert</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">M. Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Brown%2C+S+E">S. E. Brown</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="1911.02057v1-abstract-short" style="display: inline;"> We scrutinize the magnetic properties of $魏$-(BEDT-TTF)$_2$Hg(SCN)$_2$Cl through its first-order metal-insulator transition at $T_{\rm CO}=30$ K by means of $^1$H nuclear magnetic resonance (NMR). While in the metal we find Fermi-liquid behavior with temperature-independent $(T_1T)^{-1}$, the relaxation rate exhibits a pronounced enhancement when charge order sets in. The NMR spectra remain unchan… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1911.02057v1-abstract-full').style.display = 'inline'; document.getElementById('1911.02057v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1911.02057v1-abstract-full" style="display: none;"> We scrutinize the magnetic properties of $魏$-(BEDT-TTF)$_2$Hg(SCN)$_2$Cl through its first-order metal-insulator transition at $T_{\rm CO}=30$ K by means of $^1$H nuclear magnetic resonance (NMR). While in the metal we find Fermi-liquid behavior with temperature-independent $(T_1T)^{-1}$, the relaxation rate exhibits a pronounced enhancement when charge order sets in. The NMR spectra remain unchanged through the transition and no magnetic order stabilizes down to 25 mK. Similar to the isostructural spin-liquid candidates $魏$-(BEDT-TTF)$_2$Cu$_2$(CN)$_3$ and $魏$-(BEDT-TTF)$_2$Ag$_2$(CN)$_3$, $T_1^{-1}$ acquires a dominant maximum (here around 5 K). Field-dependent experiments identify the low-temperature feature as a dynamic inhomogeneity contribution that is typically dominant over the intrinsic relaxation but gets suppressed with magnetic field. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1911.02057v1-abstract-full').style.display = 'none'; document.getElementById('1911.02057v1-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> 5 November, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> November 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, 4 figures; Supplemental Material: 3 pages, 2 figures, 1 table</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. B 101, 140401 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1906.08590">arXiv:1906.08590</a> <span> [<a href="https://arxiv.org/pdf/1906.08590">pdf</a>, <a href="https://arxiv.org/ps/1906.08590">ps</a>, <a href="https://arxiv.org/format/1906.08590">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/PhysRevLett.123.027601">10.1103/PhysRevLett.123.027601 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Lattice dynamics coupled to charge and spin degrees of freedom in the molecular dimer-Mott insulator $魏$-(BEDT-TTF)$_{2}$Cu[N(CN)$_{2}$]Cl </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Matsuura%2C+M">Masato Matsuura</a>, <a href="/search/cond-mat?searchtype=author&query=Sasaki%2C+T">Takahiko Sasaki</a>, <a href="/search/cond-mat?searchtype=author&query=Iguchi%2C+S">Satoshi Iguchi</a>, <a href="/search/cond-mat?searchtype=author&query=Gati%2C+E">Elena Gati</a>, <a href="/search/cond-mat?searchtype=author&query=M%C3%BCller%2C+J">Jens M眉ller</a>, <a href="/search/cond-mat?searchtype=author&query=Stockert%2C+O">Oliver Stockert</a>, <a href="/search/cond-mat?searchtype=author&query=Piovano%2C+A">Andrea Piovano</a>, <a href="/search/cond-mat?searchtype=author&query=B%C3%B6hm%2C+M">Martin B枚hm</a>, <a href="/search/cond-mat?searchtype=author&query=Park%2C+J+T">Jitae T. Park</a>, <a href="/search/cond-mat?searchtype=author&query=Biswas%2C+S">Sananda Biswas</a>, <a href="/search/cond-mat?searchtype=author&query=Winter%2C+S+M">Stephen M. Winter</a>, <a href="/search/cond-mat?searchtype=author&query=Valent%C3%AD%2C+R">Roser Valent铆</a>, <a href="/search/cond-mat?searchtype=author&query=Nakao%2C+A">Akiko Nakao</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</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="1906.08590v3-abstract-short" style="display: inline;"> Inelastic neutron scattering measurements on the molecular dimer-Mott insulator $魏$-(BEDT-TTF)$_{2}$Cu[N(CN)$_{2}$]Cl reveal a phonon anomaly in a wide temperature range. Starting from $T_{\rm ins}\sim50$-$60$ K where the charge gap opens, the low-lying optical phonon modes become overdamped upon cooling towards the antiferromagnetic ordering temperature $T_\mathrm{N} = 27$ K, where also a ferroel… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1906.08590v3-abstract-full').style.display = 'inline'; document.getElementById('1906.08590v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1906.08590v3-abstract-full" style="display: none;"> Inelastic neutron scattering measurements on the molecular dimer-Mott insulator $魏$-(BEDT-TTF)$_{2}$Cu[N(CN)$_{2}$]Cl reveal a phonon anomaly in a wide temperature range. Starting from $T_{\rm ins}\sim50$-$60$ K where the charge gap opens, the low-lying optical phonon modes become overdamped upon cooling towards the antiferromagnetic ordering temperature $T_\mathrm{N} = 27$ K, where also a ferroelectric ordering at $T_{\rm FE} \approx T_{\rm N}$ occurs. Conversely, the phonon damping becomes small again when spins and charges are ordered below $T_\mathrm{N}$, while no change of the lattice symmetry is observed across $T_\mathrm{N}$ in neutron diffraction measurements. We assign the phonon anomalies to structural fluctuations coupled to charge and spin degrees of freedom in the BEDT-TTF molecules. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1906.08590v3-abstract-full').style.display = 'none'; document.getElementById('1906.08590v3-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> 13 December, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 20 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">6 pages, 3 figures with Erratum ( 4 pages, 2 figures) and supplemental material (4 pages, 4 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/1905.06761">arXiv:1905.06761</a> <span> [<a href="https://arxiv.org/pdf/1905.06761">pdf</a>, <a href="https://arxiv.org/format/1905.06761">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.100.174428">10.1103/PhysRevB.100.174428 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Signatures for spinons in the quantum spin liquid candidate Ca$_{10}$Cr$_7$O$_{28}$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Sonnenschein%2C+J">Jonas Sonnenschein</a>, <a href="/search/cond-mat?searchtype=author&query=Balz%2C+C">Christian Balz</a>, <a href="/search/cond-mat?searchtype=author&query=Tutsch%2C+U">Ulrich Tutsch</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Michael Lang</a>, <a href="/search/cond-mat?searchtype=author&query=Ryll%2C+H">Hanjo Ryll</a>, <a href="/search/cond-mat?searchtype=author&query=Rodriguez-Rivera%2C+J+A">Jose A. Rodriguez-Rivera</a>, <a href="/search/cond-mat?searchtype=author&query=Islam%2C+A+T+M+N">A. T. M. Nazmul Islam</a>, <a href="/search/cond-mat?searchtype=author&query=Lake%2C+B">Bella Lake</a>, <a href="/search/cond-mat?searchtype=author&query=Reuther%2C+J">Johannes Reuther</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="1905.06761v1-abstract-short" style="display: inline;"> We present new experimental low-temperature heat capacity and detailed dynamical spin-structure factor data for the quantum spin liquid candidate material Ca$_{10}$Cr$_7$O$_{28}$. The measured heat capacity shows an almost perfect linear temperature dependence in the range $0.1$ K $\lesssim T\lesssim0.5$ K, reminiscent of fermionic spinon degrees of freedom. The spin structure factor exhibits two… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1905.06761v1-abstract-full').style.display = 'inline'; document.getElementById('1905.06761v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1905.06761v1-abstract-full" style="display: none;"> We present new experimental low-temperature heat capacity and detailed dynamical spin-structure factor data for the quantum spin liquid candidate material Ca$_{10}$Cr$_7$O$_{28}$. The measured heat capacity shows an almost perfect linear temperature dependence in the range $0.1$ K $\lesssim T\lesssim0.5$ K, reminiscent of fermionic spinon degrees of freedom. The spin structure factor exhibits two energy regimes of strong signal which display rather different but solely diffuse scattering features. We theoretically describe these findings by an effective spinon hopping model which crucially relies on the existence of strong ferromagnetically coupled triangles in the system. Our spinon theory is shown to naturally reproduce the overall weight distribution of the measured spin structure factor. Particularly, we argue that various different observed characteristic properties of the spin structure factor and the heat capacity consistently indicate the existence of a spinon Fermi surface. A closer analysis of the heat capacity at the lowest accessible temperatures hints towards the presence of weak $f$-wave spinon pairing terms inducing a small partial gap along the Fermi surface (except for discrete nodal Dirac points) and suggesting an overall $\mathbb{Z}_2$ quantum spin liquid scenario for Ca$_{10}$Cr$_7$O$_{28}$. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1905.06761v1-abstract-full').style.display = 'none'; document.getElementById('1905.06761v1-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 May, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 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">14 pages, 6 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, 174428 (2019) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1905.01421">arXiv:1905.01421</a> <span> [<a href="https://arxiv.org/pdf/1905.01421">pdf</a>, <a href="https://arxiv.org/format/1905.01421">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"> Temperature-induced atomic-structure modifications in UO$_{2}$ and UO$_{2+x}$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Palomares%2C+R+I">Raul I. Palomares</a>, <a href="/search/cond-mat?searchtype=author&query=Szymanowski%2C+J+E">Jennifer E. Szymanowski</a>, <a href="/search/cond-mat?searchtype=author&query=Yao%2C+T">Tiankai Yao</a>, <a href="/search/cond-mat?searchtype=author&query=Neuefeind%2C+J">Joerg Neuefeind</a>, <a href="/search/cond-mat?searchtype=author&query=Sigmon%2C+G+E">Ginger E. Sigmon</a>, <a href="/search/cond-mat?searchtype=author&query=Lian%2C+J">Jie Lian</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Maik Lang</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="1905.01421v1-abstract-short" style="display: inline;"> UO$_{2}$ and UO$_{2.07}$ were characterized from 25-1000$\,^{\circ}\mathrm{C}$ using neutron total scattering in order to evaluate effects of temperature and phase boundaries on local and average structures. Analyses of unit cell parameters showed that both materials exhibit very similar thermal expansion behavior and thermal expansion data lay along the upper bound of uncertainty for standard emp… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1905.01421v1-abstract-full').style.display = 'inline'; document.getElementById('1905.01421v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1905.01421v1-abstract-full" style="display: none;"> UO$_{2}$ and UO$_{2.07}$ were characterized from 25-1000$\,^{\circ}\mathrm{C}$ using neutron total scattering in order to evaluate effects of temperature and phase boundaries on local and average structures. Analyses of unit cell parameters showed that both materials exhibit very similar thermal expansion behavior and thermal expansion data lay along the upper bound of uncertainty for standard empirical models, indicating a slightly faster thermal expansion rate. Atomic displacement parameters of UO$_{2.07}$ showed evidence for U$_{4}$O$_{9}$ phase boundaries in accordance with the established phase diagram, despite the suppression of U$_{4}$O$_{9}$ superlattice peaks in the measured diffraction patterns. Pair distribution functions revealed that the differences in local structure between UO$_{2}$ and UO$_{2.07}$ were very small and PDF features are dominated by thermal effects. The rate of contraction of the first nearest-neighbor U-O distances of UO$_{2}$ and UO$_{2.07}$ between 25-1000$\,^{\circ}\mathrm{C}$ were shown to agree with molecular dynamics simulations and local structure analyses previously performed on UO$_{2}$ above 1000$\,^{\circ}\mathrm{C}$. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1905.01421v1-abstract-full').style.display = 'none'; document.getElementById('1905.01421v1-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 May, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 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">11 pages, 8 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/1902.01099">arXiv:1902.01099</a> <span> [<a href="https://arxiv.org/pdf/1902.01099">pdf</a>, <a href="https://arxiv.org/format/1902.01099">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/10.1002/pssb.201900044">10.1002/pssb.201900044 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Magneto-structural properties of the layered quasi-2D triangular-lattice antiferromagnets Cs$_2$CuCl$_{4-x}$Br$_x$ for ${x}$ = 0,1,2 and 4 </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Thallapaka%2C+S+K">S. K. Thallapaka</a>, <a href="/search/cond-mat?searchtype=author&query=Wolf%2C+B">B. Wolf</a>, <a href="/search/cond-mat?searchtype=author&query=Gati%2C+E">E. Gati</a>, <a href="/search/cond-mat?searchtype=author&query=Postulka%2C+L">L. Postulka</a>, <a href="/search/cond-mat?searchtype=author&query=Tutsch%2C+U">U. Tutsch</a>, <a href="/search/cond-mat?searchtype=author&query=Schmidt%2C+B">B. Schmidt</a>, <a href="/search/cond-mat?searchtype=author&query=Thalmeier%2C+P">P. Thalmeier</a>, <a href="/search/cond-mat?searchtype=author&query=Ritter%2C+F">F. Ritter</a>, <a href="/search/cond-mat?searchtype=author&query=Krellner%2C+C">C. Krellner</a>, <a href="/search/cond-mat?searchtype=author&query=Li%2C+Y">Y. Li</a>, <a href="/search/cond-mat?searchtype=author&query=Borisov%2C+V">V. Borisov</a>, <a href="/search/cond-mat?searchtype=author&query=Valent%C3%AD%2C+R">R. Valent铆</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">M. Lang</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="1902.01099v1-abstract-short" style="display: inline;"> We present a study of the magnetic susceptibility $蠂_{mol}$ under variable hydrostatic pressure on single crystals of Cs$_2$CuCl$_{4-x}$Br$_x$. This includes the border compounds \textit{x} = 0 and 4, known as good realizations of the distorted triangular-lattice spin-1/2 Heisenberg antiferromagnet, as well as the isostructural stoichiometric systems Cs$_2$CuCl$_{3}$Br$_1$ and Cs$_2$CuCl$_{2}$Br… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1902.01099v1-abstract-full').style.display = 'inline'; document.getElementById('1902.01099v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1902.01099v1-abstract-full" style="display: none;"> We present a study of the magnetic susceptibility $蠂_{mol}$ under variable hydrostatic pressure on single crystals of Cs$_2$CuCl$_{4-x}$Br$_x$. This includes the border compounds \textit{x} = 0 and 4, known as good realizations of the distorted triangular-lattice spin-1/2 Heisenberg antiferromagnet, as well as the isostructural stoichiometric systems Cs$_2$CuCl$_{3}$Br$_1$ and Cs$_2$CuCl$_{2}$Br$_2$. For the determination of the exchange coupling constants $J$ and $J^{\prime}$, $蠂_{mol}$ data were fitted by a $J-J^{\prime}$ model \cite{Schmidt2015}. Its application, validated for the border compounds, yields a degree of frustration $J^{\prime}$/$J$ = 0.47 for Cs$_2$CuCl$_3$Br$_1$ and $J^{\prime}$/$J$ $\simeq$ 0.63 - 0.78 for Cs$_2$CuCl$_2$Br$_2$, making these systems particular interesting representatives of this family. From the evolution of the magnetic susceptibility under pressure up to about 0.4\,GPa, the maximum pressure applied, two observations were made for all the compounds investigated here. First, we find that the overall energy scale, given by $J_c = (J^2$ + $J^{\prime 2}$)$^{1/2}$, increases under pressure, whereas the ratio $J^{\prime}$/$J$ remains unchanged in this pressure range. These experimental observations are in accordance with the results of DFT calculations performed for these materials. Secondly, for the magnetoelastic coupling constants, extraordinarily small values are obtained. We assign these observations to a structural peculiarity of this class of materials. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1902.01099v1-abstract-full').style.display = 'none'; document.getElementById('1902.01099v1-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 February, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2019. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1901.07799">arXiv:1901.07799</a> <span> [<a href="https://arxiv.org/pdf/1901.07799">pdf</a>, <a href="https://arxiv.org/format/1901.07799">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/PhysRevLett.123.147202">10.1103/PhysRevLett.123.147202 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Specific Heat Study of 1D and 2D Excitations in the Layered Frustrated Quantum Antiferromagnets Cs$_2$CuCl$_{4-x}$Br$_x$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Tutsch%2C+U">U. Tutsch</a>, <a href="/search/cond-mat?searchtype=author&query=Tsyplyatyev%2C+O">O. Tsyplyatyev</a>, <a href="/search/cond-mat?searchtype=author&query=Kuhnt%2C+M">M. Kuhnt</a>, <a href="/search/cond-mat?searchtype=author&query=Postulka%2C+L">L. Postulka</a>, <a href="/search/cond-mat?searchtype=author&query=Wolf%2C+B">B. Wolf</a>, <a href="/search/cond-mat?searchtype=author&query=Cong%2C+P+T">P. T. Cong</a>, <a href="/search/cond-mat?searchtype=author&query=Ritter%2C+F">F. Ritter</a>, <a href="/search/cond-mat?searchtype=author&query=Krellner%2C+C">C. Krellner</a>, <a href="/search/cond-mat?searchtype=author&query=A%C3%9Fmus%2C+W">W. A脽mus</a>, <a href="/search/cond-mat?searchtype=author&query=Schmidt%2C+B">B. Schmidt</a>, <a href="/search/cond-mat?searchtype=author&query=Thalmeier%2C+P">P. Thalmeier</a>, <a href="/search/cond-mat?searchtype=author&query=Kopietz%2C+P">P. Kopietz</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">M. Lang</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="1901.07799v1-abstract-short" style="display: inline;"> We report an experimental and theoretical study of the low-temperature specific heat $C$ and magnetic susceptibility $蠂$ of the layered anisotropic triangular-lattice spin-1/2 Heisenberg antiferromagnets Cs$_2$CuCl$_{4-x}$Br$_x$ with $x$ = 0, 1, 2, and 4. We find that the ratio $J'/J$ of the exchange couplings ranges from 0.32 to $\approx 0.78$, implying a change (crossover or quantum phase transi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1901.07799v1-abstract-full').style.display = 'inline'; document.getElementById('1901.07799v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1901.07799v1-abstract-full" style="display: none;"> We report an experimental and theoretical study of the low-temperature specific heat $C$ and magnetic susceptibility $蠂$ of the layered anisotropic triangular-lattice spin-1/2 Heisenberg antiferromagnets Cs$_2$CuCl$_{4-x}$Br$_x$ with $x$ = 0, 1, 2, and 4. We find that the ratio $J'/J$ of the exchange couplings ranges from 0.32 to $\approx 0.78$, implying a change (crossover or quantum phase transition) in the materials' magnetic properties from one-dimensional (1D) behavior for $J'/J < 0.6$ to two-dimensional (2D) behavior for $J'/J \approx 0.78$ behavior. For $J'/J < 0.6$, realized for $x$ = 0, 1, and 4, we find a magnetic contribution to the low-temperature specific heat, $C_{\rm m} \propto T$, consistent with spinon excitations in 1D spin-1/2 Heisenberg antiferromagnets. Remarkably, for $x$ = 2, where $J'/J \approx 0.78$ implies a 2D magnatic character, we also observe $C_{\rm m} \propto T$. This finding, which contrasts the prediction of $C_{\rm m} \propto T^2$ made by standard spin-wave theories, shows that Fermi-like statistics also plays a significant role for the magnetic excitations in frustrated spin-1/2 2D antiferromagnets. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1901.07799v1-abstract-full').style.display = 'none'; document.getElementById('1901.07799v1-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> 23 January, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 123, 147202 (2019) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1901.06663">arXiv:1901.06663</a> <span> [<a href="https://arxiv.org/pdf/1901.06663">pdf</a>, <a href="https://arxiv.org/ps/1901.06663">ps</a>, <a href="https://arxiv.org/format/1901.06663">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="Instrumentation and Methods for Astrophysics">astro-ph.IM</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="High Energy Physics - Experiment">hep-ex</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Nuclear Experiment">nucl-ex</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/10.1016/j.nima.2019.02.006">10.1016/j.nima.2019.02.006 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Developing a silica aerogel radiator for the HELIX ring-imaging Cherenkov system </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/cond-mat?searchtype=author&query=Tabata%2C+M">Makoto Tabata</a>, <a href="/search/cond-mat?searchtype=author&query=Allison%2C+P">Patrick Allison</a>, <a href="/search/cond-mat?searchtype=author&query=Beatty%2C+J+J">James J. Beatty</a>, <a href="/search/cond-mat?searchtype=author&query=Coutu%2C+S">Stephane Coutu</a>, <a href="/search/cond-mat?searchtype=author&query=Gebhard%2C+M">Mark Gebhard</a>, <a href="/search/cond-mat?searchtype=author&query=Green%2C+N">Noah Green</a>, <a href="/search/cond-mat?searchtype=author&query=Hanna%2C+D">David Hanna</a>, <a href="/search/cond-mat?searchtype=author&query=Kunkler%2C+B">Brandon Kunkler</a>, <a href="/search/cond-mat?searchtype=author&query=Lang%2C+M">Mike Lang</a>, <a href="/search/cond-mat?searchtype=author&query=McBride%2C+K">Keith McBride</a>, <a href="/search/cond-mat?searchtype=author&query=Mognet%2C+I">Isaac Mognet</a>, <a href="/search/cond-mat?searchtype=author&query=M%C3%BCller%2C+D">Dietrich M眉ller</a>, <a href="/search/cond-mat?searchtype=author&query=Musser%2C+J">James Musser</a>, <a href="/search/cond-mat?searchtype=author&query=Nutter%2C+S">Scott Nutter</a>, <a href="/search/cond-mat?searchtype=author&query=Park%2C+N">Nahee Park</a>, <a href="/search/cond-mat?searchtype=author&query=Schubnell%2C+M">Michael Schubnell</a>, <a href="/search/cond-mat?searchtype=author&query=Tarl%C3%A9%2C+G">Gregory Tarl茅</a>, <a href="/search/cond-mat?searchtype=author&query=Tomasch%2C+A">Andrew Tomasch</a>, <a href="/search/cond-mat?searchtype=author&query=Visser%2C+G">Gerard Visser</a>, <a href="/search/cond-mat?searchtype=author&query=Wakely%2C+S+P">Scott P. Wakely</a>, <a href="/search/cond-mat?searchtype=author&query=Wisher%2C+I">Ian Wisher</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="1901.06663v1-abstract-short" style="display: inline;"> This paper reports the successful fabrication of silica aerogel Cherenkov radiators produced in the first batches from a 96-tile mass production performed using pin-drying technique in our laboratory. The aerogels are to be used in a ring-imaging Cherenkov detector in the spectrometer of a planned balloon-borne cosmic-ray observation program, HELIX (High Energy Light Isotope eXperiment). A total o… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1901.06663v1-abstract-full').style.display = 'inline'; document.getElementById('1901.06663v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1901.06663v1-abstract-full" style="display: none;"> This paper reports the successful fabrication of silica aerogel Cherenkov radiators produced in the first batches from a 96-tile mass production performed using pin-drying technique in our laboratory. The aerogels are to be used in a ring-imaging Cherenkov detector in the spectrometer of a planned balloon-borne cosmic-ray observation program, HELIX (High Energy Light Isotope eXperiment). A total of 36 transparent, hydrophobic aerogel tiles with a high refractive index of 1.16 and dimensions of 10 cm $\times $ 10 cm $\times $ 1 cm will be chosen as the flight radiators. Thus far, 40 out of the 48 tiles fabricated were confirmed as having no tile cracking. In the first screening, 8 out of the first 16 tiles were accepted as flight-qualified candidates, based on basic optical measurement results. To fit the aerogel tiles into a radiator support structure, the trimming of previously manufactured prototype tiles using a water-jet cutting device was successful. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1901.06663v1-abstract-full').style.display = 'none'; document.getElementById('1901.06663v1-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 January, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 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">Submitted to Nucl. Instrum. Methods Phys. Res. A (NIMA Proc. Special Issue: RICH 2018), 5 pages, 6 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Nuclear Instruments and Methods in Physics Research A 952 (2020) 161879 </p> </li> </ol> <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=Lang%2C+M&start=50" class="pagination-next" >Next </a> <ul class="pagination-list"> <li> <a href="/search/?searchtype=author&query=Lang%2C+M&start=0" class="pagination-link is-current" aria-label="Goto page 1">1 </a> </li> <li> <a href="/search/?searchtype=author&query=Lang%2C+M&start=50" class="pagination-link " aria-label="Page 2" aria-current="page">2 </a> </li> <li> <a href="/search/?searchtype=author&query=Lang%2C+M&start=100" class="pagination-link " aria-label="Page 3" aria-current="page">3 </a> </li> </ul> </nav> 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