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name="searchtype"><option value="all">All fields</option><option value="title">Title</option><option selected value="author">Author(s)</option><option value="abstract">Abstract</option><option value="comments">Comments</option><option value="journal_ref">Journal reference</option><option value="acm_class">ACM classification</option><option value="msc_class">MSC classification</option><option value="report_num">Report number</option><option value="paper_id">arXiv identifier</option><option value="doi">DOI</option><option value="orcid">ORCID</option><option value="license">License (URI)</option><option value="author_id">arXiv author ID</option><option value="help">Help pages</option><option value="full_text">Full text</option></select> <input id="query" name="query" type="text" value="Xie, T"> <ul id="abstracts"><li><input checked id="abstracts-0" name="abstracts" type="radio" value="show"> <label for="abstracts-0">Show abstracts</label></li><li><input id="abstracts-1" name="abstracts" 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is-link">Go</button> </div> </div> </form> </div> </div> <ol class="breathe-horizontal" start="1"> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2410.13266">arXiv:2410.13266</a> <span> [<a href="https://arxiv.org/pdf/2410.13266">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Physics and Society">physics.soc-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/10.1016/j.ssci.2024.106576">10.1016/j.ssci.2024.106576 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Continuous agent-based modeling of adult-child pairs based on a pseudo-energy: Relevance for public safety and egress efficiency </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Xie%2C+C+T">Chuan-Zhi Thomas Xie</a>, <a href="/search/physics?searchtype=author&query=Tang%2C+T">Tie-Qiao Tang</a>, <a href="/search/physics?searchtype=author&query=Nicolas%2C+A">Alexandre Nicolas</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2410.13266v1-abstract-short" style="display: inline;"> Pushes, falls, stampedes, and crushes are safety hazards that emerge from the collective motion of crowds, but might be avoided by better design and guidance. While pedestrian dynamics are now getting better understood on the whole, complex heterogeneous flows involvinge.g. adult-child pairs, though widely found at e.g. crowded Chinese training schools, still defy the current understanding and cap… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.13266v1-abstract-full').style.display = 'inline'; document.getElementById('2410.13266v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2410.13266v1-abstract-full" style="display: none;"> Pushes, falls, stampedes, and crushes are safety hazards that emerge from the collective motion of crowds, but might be avoided by better design and guidance. While pedestrian dynamics are now getting better understood on the whole, complex heterogeneous flows involvinge.g. adult-child pairs, though widely found at e.g. crowded Chinese training schools, still defy the current understanding and capabilities of crowd simulation models. We substantially extend a recent agent-based model in which each agent's choice of motion results from the minimization ofa sum of intuitive contributions, in order to integrate adult-child pairs. This is achieved by adding a suitably defined pairing potential. The resulting model captures the relative positions of pair members in a quantitative fashion, as confirmed by small-scale controlled experiments, and alsosucceeds in describing collision avoidance between pairs. The model is used to simulate mixed adult-child flows at a T-junction and test the sensitivity to the design and pairing strategies. Simulation shows that making the post-confluence corridor wide enough is critical to avoidfriction in the flow, and that tight hand-holding is advisable for safer evacuations (whereas more loosely bound pairs get split at high density) and, more marginally, more efficient egresses in normal conditions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2410.13266v1-abstract-full').style.display = 'none'; document.getElementById('2410.13266v1-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 October, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Safety Science, 2024, 177, pp.106576 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2406.16017">arXiv:2406.16017</a> <span> [<a href="https://arxiv.org/pdf/2406.16017">pdf</a>, <a href="https://arxiv.org/format/2406.16017">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> </div> </div> <p class="title is-5 mathjax"> Competing excitation quenching and charge exchange in ultracold Li-Ba$^+$ collisions </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Xing%2C+X">Xiaodong Xing</a>, <a href="/search/physics?searchtype=author&query=Weckesser%2C+P">Pascal Weckesser</a>, <a href="/search/physics?searchtype=author&query=Thielemann%2C+F">Fabian Thielemann</a>, <a href="/search/physics?searchtype=author&query=J%C3%B3n%C3%A1s%2C+T">Tibor J贸n谩s</a>, <a href="/search/physics?searchtype=author&query=Vexiau%2C+R">Romain Vexiau</a>, <a href="/search/physics?searchtype=author&query=Bouloufa-Maafa%2C+N">Nadia Bouloufa-Maafa</a>, <a href="/search/physics?searchtype=author&query=Luc-Koenig%2C+E">Eliane Luc-Koenig</a>, <a href="/search/physics?searchtype=author&query=Madison%2C+K+W">Kirk W. Madison</a>, <a href="/search/physics?searchtype=author&query=Orb%C3%A1n%2C+A">Andrea Orb谩n</a>, <a href="/search/physics?searchtype=author&query=Xie%2C+T">Ting Xie</a>, <a href="/search/physics?searchtype=author&query=Schaetz%2C+T">Tobias Schaetz</a>, <a href="/search/physics?searchtype=author&query=Dulieu%2C+O">Olivier Dulieu</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2406.16017v1-abstract-short" style="display: inline;"> Hybrid atom-ion systems are a rich and powerful platform for studying chemical reactions, as they feature both excellent control over the electronic state preparation and readout as well as a versatile tunability over the scattering energy, ranging from the few-partial wave regime to the quantum regime. In this work, we make use of these excellent control knobs, and present a joint experimental an… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.16017v1-abstract-full').style.display = 'inline'; document.getElementById('2406.16017v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2406.16017v1-abstract-full" style="display: none;"> Hybrid atom-ion systems are a rich and powerful platform for studying chemical reactions, as they feature both excellent control over the electronic state preparation and readout as well as a versatile tunability over the scattering energy, ranging from the few-partial wave regime to the quantum regime. In this work, we make use of these excellent control knobs, and present a joint experimental and theoretical study of the collisions of a single $^{138}$Ba$^+$ ion prepared in the $5d\,^2D_{3/2,5/2}$ metastable states with a ground state $^6$Li gas near quantum degeneracy. We show that in contrast to previously reported atom-ion mixtures, several non-radiative processes, including charge exchange, excitation exchange and quenching, compete with each other due to the inherent complexity of the ion-atom molecular structure. We present a full quantum model based on high-level electronic structure calculations involving spin-orbit couplings. Results are in excellent agreement with observations, highlighting the strong coupling between the internal angular momenta and the mechanical rotation of the colliding pair, which is relevant in any other hybrid system composed of an alkali-metal atom and an alkaline-earth ion. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2406.16017v1-abstract-full').style.display = 'none'; document.getElementById('2406.16017v1-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 June, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2024. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">17 pages, 15 figures, 4 tables</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2405.08074">arXiv:2405.08074</a> <span> [<a href="https://arxiv.org/pdf/2405.08074">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Strongly Correlated Electrons">cond-mat.str-el</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> </div> </div> <p class="title is-5 mathjax"> Optical Imaging of Flavor Order in Flat Band Graphene </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Xie%2C+T">Tian Xie</a>, <a href="/search/physics?searchtype=author&query=Wolf%2C+T+M">Tobias M. Wolf</a>, <a href="/search/physics?searchtype=author&query=Xu%2C+S">Siyuan Xu</a>, <a href="/search/physics?searchtype=author&query=Cui%2C+Z">Zhiyuan Cui</a>, <a href="/search/physics?searchtype=author&query=Xiong%2C+R">Richen Xiong</a>, <a href="/search/physics?searchtype=author&query=Ou%2C+Y">Yunbo Ou</a>, <a href="/search/physics?searchtype=author&query=Hays%2C+P">Patrick Hays</a>, <a href="/search/physics?searchtype=author&query=Holleis%2C+L+F">Ludwig F Holleis</a>, <a href="/search/physics?searchtype=author&query=Guo%2C+Y">Yi Guo</a>, <a href="/search/physics?searchtype=author&query=Sheekey%2C+O+I">Owen I Sheekey</a>, <a href="/search/physics?searchtype=author&query=Patterson%2C+C">Caitlin Patterson</a>, <a href="/search/physics?searchtype=author&query=Arp%2C+T">Trevor Arp</a>, <a href="/search/physics?searchtype=author&query=Watanabe%2C+K">Kenji Watanabe</a>, <a href="/search/physics?searchtype=author&query=Taniguchi%2C+T">Takashi Taniguchi</a>, <a href="/search/physics?searchtype=author&query=Tongay%2C+S+A">Seth Ariel Tongay</a>, <a href="/search/physics?searchtype=author&query=Young%2C+A+F">Andrea F Young</a>, <a href="/search/physics?searchtype=author&query=MacDonald%2C+A+H">Allan H. MacDonald</a>, <a href="/search/physics?searchtype=author&query=Jin%2C+C">Chenhao Jin</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2405.08074v1-abstract-short" style="display: inline;"> Spin and valley flavor polarization plays a central role in the many-body physics of flat band graphene, with fermi surface reconstructions often accompanied by quantized anomalous Hall and superconducting state observed in a variety of experimental systems. Here we describe an optical technique that sensitively and selectively detects flavor textures via the exciton response of a proximal transit… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.08074v1-abstract-full').style.display = 'inline'; document.getElementById('2405.08074v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2405.08074v1-abstract-full" style="display: none;"> Spin and valley flavor polarization plays a central role in the many-body physics of flat band graphene, with fermi surface reconstructions often accompanied by quantized anomalous Hall and superconducting state observed in a variety of experimental systems. Here we describe an optical technique that sensitively and selectively detects flavor textures via the exciton response of a proximal transition metal dichalcogenide layer. Through a systematic study of rhombohedral and rotationally faulted graphene bilayers and trilayers, we show that when the semiconducting dichalcogenide is in direct contact with the graphene, the exciton response is most sensitive to the large momentum rearrangement of the Fermi surface, providing information that is distinct from and complementary to electrical compressibility measurements. The wide-field imaging capability of optical probes allows us to obtain spatial maps of flavor orders with high throughput, and with broad temperature and device compatibility. Our work paves the way for optical probing and imaging of flavor orders in flat band graphene systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2405.08074v1-abstract-full').style.display = 'none'; document.getElementById('2405.08074v1-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 May, 2024; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 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">29 pages, 4 figures, with supplementary materials</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2401.02967">arXiv:2401.02967</a> <span> [<a href="https://arxiv.org/pdf/2401.02967">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> </div> </div> <p class="title is-5 mathjax"> Large enhancement of spin-orbit torques under a MHz modulation due to phonon-magnon coupling </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Zhang%2C+H">Hanying Zhang</a>, <a href="/search/physics?searchtype=author&query=Zhao%2C+Q">Qianwen Zhao</a>, <a href="/search/physics?searchtype=author&query=Jiang%2C+B">Baiqing Jiang</a>, <a href="/search/physics?searchtype=author&query=Wang%2C+Y">Yuan Wang</a>, <a href="/search/physics?searchtype=author&query=Xie%2C+T">Tunan Xie</a>, <a href="/search/physics?searchtype=author&query=Lou%2C+K">Kaihua Lou</a>, <a href="/search/physics?searchtype=author&query=Xia%2C+C">ChaoChao Xia</a>, <a href="/search/physics?searchtype=author&query=Bi%2C+C">C. Bi</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="2401.02967v1-abstract-short" style="display: inline;"> The discovery of spin-orbit torques (SOTs) generated through the spin Hall or Rashba effects provides an alternative write approach for magnetic random-access memory (MRAM), igniting the development of spin-orbitronics in recent years. Quantitative characterization of SOTs highly relies on the SOT-driven ferromagnetic resonance (ST-FMR), where a modulated microwave current is used to generate ac S… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.02967v1-abstract-full').style.display = 'inline'; document.getElementById('2401.02967v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2401.02967v1-abstract-full" style="display: none;"> The discovery of spin-orbit torques (SOTs) generated through the spin Hall or Rashba effects provides an alternative write approach for magnetic random-access memory (MRAM), igniting the development of spin-orbitronics in recent years. Quantitative characterization of SOTs highly relies on the SOT-driven ferromagnetic resonance (ST-FMR), where a modulated microwave current is used to generate ac SOTs and the modulation-frequency is usually less than 100 kHz (the limit of conventional lock-in amplifiers). Here we have investigated the SOT of typical SOT material/ferromagnet bilayers in an extended modulation-frequency range, up to MHz, by developing the ST-FMR measurement. Remarkably, we found that the measured SOTs are enhanced about three times in the MHz range, which cannot be explained according to present SOT theory. We attribute the enhancement of SOT to additional magnon excitations due to phonon-magnon coupling, which is also reflected in the slight changes of resonant field and linewidth in the acquired ST-FMR spectra, corresponding to the modifications of effective magnetization and damping constant, respectively. Our results indicate that the write current of SOT-MRAM may be reduced with the assistant of phonon-magnon coupling. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2401.02967v1-abstract-full').style.display = 'none'; document.getElementById('2401.02967v1-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 December, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> January 2024. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2312.05204">arXiv:2312.05204</a> <span> [<a href="https://arxiv.org/pdf/2312.05204">pdf</a>, <a href="https://arxiv.org/ps/2312.05204">ps</a>, <a href="https://arxiv.org/format/2312.05204">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Fluid Dynamics">physics.flu-dyn</span> </div> </div> <p class="title is-5 mathjax"> Stoichiometry preservation and generalization of Bilger mixture fraction for non-premixed combustion with differential molecular diffusion </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Wang%2C+H">Haifeng Wang</a>, <a href="/search/physics?searchtype=author&query=Xie%2C+T">Tianfang Xie</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="2312.05204v1-abstract-short" style="display: inline;"> The Bilger mixture fraction is a widely used parameter in non-premixed combustion when considering differential molecular diffusion, a prevalent phenomenon in hydrogen or hydrogen-blended fuel combustion. The property of stoichiometry preservation of mixture fractions is investigated. Two different Bilger mixture fraction formulations are clarified. It is found that they belong to a class of one-p… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.05204v1-abstract-full').style.display = 'inline'; document.getElementById('2312.05204v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2312.05204v1-abstract-full" style="display: none;"> The Bilger mixture fraction is a widely used parameter in non-premixed combustion when considering differential molecular diffusion, a prevalent phenomenon in hydrogen or hydrogen-blended fuel combustion. The property of stoichiometry preservation of mixture fractions is investigated. Two different Bilger mixture fraction formulations are clarified. It is found that they belong to a class of one-parameter generalized mixture fraction definitions discovered in this work. Specific definitions from the class of mixture fractions are compared for hydrocarbon fuels. The comparison shows that the difference can be significant. An optimal mixture fraction definition is sought from the general definitions by minimizing its deviation from the desired properties. The obtained optimal mixture fractions show overall better preservation of stoichiometry than Bilger's definitions. The extension of the generalized mixture fraction to other fuels that contain nitrogen (like ammonia $\mathrm{NH_3}$) or sulfur (like hydrogen sulfide $\mathrm{H_2S}$) is also demonstrated. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2312.05204v1-abstract-full').style.display = 'none'; document.getElementById('2312.05204v1-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 December, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2310.10732">arXiv:2310.10732</a> <span> [<a href="https://arxiv.org/pdf/2310.10732">pdf</a>, <a href="https://arxiv.org/format/2310.10732">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Chemical Physics">physics.chem-ph</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="Machine Learning">cs.LG</span> </div> </div> <p class="title is-5 mathjax"> MOFDiff: Coarse-grained Diffusion for Metal-Organic Framework Design </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Fu%2C+X">Xiang Fu</a>, <a href="/search/physics?searchtype=author&query=Xie%2C+T">Tian Xie</a>, <a href="/search/physics?searchtype=author&query=Rosen%2C+A+S">Andrew S. Rosen</a>, <a href="/search/physics?searchtype=author&query=Jaakkola%2C+T">Tommi Jaakkola</a>, <a href="/search/physics?searchtype=author&query=Smith%2C+J">Jake Smith</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="2310.10732v1-abstract-short" style="display: inline;"> Metal-organic frameworks (MOFs) are of immense interest in applications such as gas storage and carbon capture due to their exceptional porosity and tunable chemistry. Their modular nature has enabled the use of template-based methods to generate hypothetical MOFs by combining molecular building blocks in accordance with known network topologies. However, the ability of these methods to identify t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.10732v1-abstract-full').style.display = 'inline'; document.getElementById('2310.10732v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2310.10732v1-abstract-full" style="display: none;"> Metal-organic frameworks (MOFs) are of immense interest in applications such as gas storage and carbon capture due to their exceptional porosity and tunable chemistry. Their modular nature has enabled the use of template-based methods to generate hypothetical MOFs by combining molecular building blocks in accordance with known network topologies. However, the ability of these methods to identify top-performing MOFs is often hindered by the limited diversity of the resulting chemical space. In this work, we propose MOFDiff: a coarse-grained (CG) diffusion model that generates CG MOF structures through a denoising diffusion process over the coordinates and identities of the building blocks. The all-atom MOF structure is then determined through a novel assembly algorithm. Equivariant graph neural networks are used for the diffusion model to respect the permutational and roto-translational symmetries. We comprehensively evaluate our model's capability to generate valid and novel MOF structures and its effectiveness in designing outstanding MOF materials for carbon capture applications with molecular simulations. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2310.10732v1-abstract-full').style.display = 'none'; document.getElementById('2310.10732v1-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 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">19 pages, 12 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/2308.13565">arXiv:2308.13565</a> <span> [<a href="https://arxiv.org/pdf/2308.13565">pdf</a>, <a href="https://arxiv.org/format/2308.13565">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Computation and Language">cs.CL</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="Applied Physics">physics.app-ph</span> </div> </div> <p class="title is-5 mathjax"> DARWIN Series: Domain Specific Large Language Models for Natural Science </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Xie%2C+T">Tong Xie</a>, <a href="/search/physics?searchtype=author&query=Wan%2C+Y">Yuwei Wan</a>, <a href="/search/physics?searchtype=author&query=Huang%2C+W">Wei Huang</a>, <a href="/search/physics?searchtype=author&query=Yin%2C+Z">Zhenyu Yin</a>, <a href="/search/physics?searchtype=author&query=Liu%2C+Y">Yixuan Liu</a>, <a href="/search/physics?searchtype=author&query=Wang%2C+S">Shaozhou Wang</a>, <a href="/search/physics?searchtype=author&query=Linghu%2C+Q">Qingyuan Linghu</a>, <a href="/search/physics?searchtype=author&query=Kit%2C+C">Chunyu Kit</a>, <a href="/search/physics?searchtype=author&query=Grazian%2C+C">Clara Grazian</a>, <a href="/search/physics?searchtype=author&query=Zhang%2C+W">Wenjie Zhang</a>, <a href="/search/physics?searchtype=author&query=Razzak%2C+I">Imran Razzak</a>, <a href="/search/physics?searchtype=author&query=Hoex%2C+B">Bram Hoex</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="2308.13565v1-abstract-short" style="display: inline;"> Emerging tools bring forth fresh approaches to work, and the field of natural science is no different. In natural science, traditional manual, serial, and labour-intensive work is being augmented by automated, parallel, and iterative processes driven by artificial intelligence-based experimental automation and more. To add new capabilities in natural science, enabling the acceleration and enrichme… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.13565v1-abstract-full').style.display = 'inline'; document.getElementById('2308.13565v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2308.13565v1-abstract-full" style="display: none;"> Emerging tools bring forth fresh approaches to work, and the field of natural science is no different. In natural science, traditional manual, serial, and labour-intensive work is being augmented by automated, parallel, and iterative processes driven by artificial intelligence-based experimental automation and more. To add new capabilities in natural science, enabling the acceleration and enrichment of automation of the discovery process, we present DARWIN, a series of tailored LLMs for natural science, mainly in physics, chemistry, and material science. This series relies on open-source LLM, incorporating structured and unstructured scientific knowledge from public datasets and literature. We fine-tuned the models using over 60,000 instruction data points, emphasizing factual correctness. During the fine-tuning, we introduce the Scientific Instruction Generation (SIG) model, automating instruction generation from scientific texts. This eliminates the need for manual extraction or domain-specific knowledge graphs and efficiently injects scientific knowledge into the model. We also explore multi-task training strategies, revealing interconnections between scientific tasks. DARWIN series not only achieves state-of-the-art results on various scientific tasks but also diminishes reliance on closed-source AI models. Our research showcases the ability of LLM in the scientific domain, with the overarching goal of fostering prosperity within the broader AI for science community. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2308.13565v1-abstract-full').style.display = 'none'; document.getElementById('2308.13565v1-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 August, 2023; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> August 2023. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2302.00553">arXiv:2302.00553</a> <span> [<a href="https://arxiv.org/pdf/2302.00553">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="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> </div> </div> <p class="title is-5 mathjax"> Ferromagnetism of sputtered Fe3GeTe2 ultrathin films in the absence of two-dimensional crystalline order </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Zhao%2C+Q">Qianwen Zhao</a>, <a href="/search/physics?searchtype=author&query=Xia%2C+C">ChaoChao Xia</a>, <a href="/search/physics?searchtype=author&query=Zhang%2C+H">Hanying Zhang</a>, <a href="/search/physics?searchtype=author&query=Jiang%2C+B">Baiqing Jiang</a>, <a href="/search/physics?searchtype=author&query=Xie%2C+T">Tunan Xie</a>, <a href="/search/physics?searchtype=author&query=Lou%2C+K">Kaihua Lou</a>, <a href="/search/physics?searchtype=author&query=Bi%2C+C">Chong Bi</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="2302.00553v1-abstract-short" style="display: inline;"> The discovery of ferromagnetism in two-dimensional (2D) monolayers has stimulated growing research interest in both spintronics and material science. However, these 2D ferromagnetic layers are mainly prepared through an incompatible approach for large-scale fabrication and integration, and moreover, a fundamental question whether the observed ferromagnetism actually correlates with the 2D crystall… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.00553v1-abstract-full').style.display = 'inline'; document.getElementById('2302.00553v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2302.00553v1-abstract-full" style="display: none;"> The discovery of ferromagnetism in two-dimensional (2D) monolayers has stimulated growing research interest in both spintronics and material science. However, these 2D ferromagnetic layers are mainly prepared through an incompatible approach for large-scale fabrication and integration, and moreover, a fundamental question whether the observed ferromagnetism actually correlates with the 2D crystalline order has not been explored. Here, we choose a typical 2D ferromagnetic material, Fe3GeTe2, to address these two issues by investigating its ferromagnetism in an amorphous state. We have fabricated nanometer-thick amorphous Fe3GeTe2 films approaching the monolayer thickness limit of crystallized Fe3GeTe2 (0.8 nm) through magnetron sputtering. Compared to crystallized Fe3GeTe2, we found that the basic ferromagnetic attributes, such as the Curie temperature that directly reflects magnetic exchange interactions and local anisotropic energy, do not change significantly in the amorphous states. This is attributed to that the short-range atomic order, as confirmed by valence state analysis, is almost the same for both phases. The persistence of ferromagnetism in the ultrathin amorphous counterpart has also been confirmed through magnetoresistance measurements, where two unconventional switching dips arising from electrical transport within domain walls are clearly observed in the amorphous Fe3GeTe2 single layer. These results indicate that the long-range ferromagnetic order of crystallized Fe3GeTe2 may not correlate to the 2D crystalline order and the corresponding ferromagnetic attributes can be utilized in an amorphous state which suits large-scale fabrication in a semiconductor technology-compatible manner for spintronics applications. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2302.00553v1-abstract-full').style.display = 'none'; document.getElementById('2302.00553v1-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 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">Comments:</span> <span class="has-text-grey-dark mathjax">27 pages, 5 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/2210.07237">arXiv:2210.07237</a> <span> [<a href="https://arxiv.org/pdf/2210.07237">pdf</a>, <a href="https://arxiv.org/format/2210.07237">other</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="Machine Learning">cs.LG</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Chemical Physics">physics.chem-ph</span> </div> </div> <p class="title is-5 mathjax"> Forces are not Enough: Benchmark and Critical Evaluation for Machine Learning Force Fields with Molecular Simulations </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Fu%2C+X">Xiang Fu</a>, <a href="/search/physics?searchtype=author&query=Wu%2C+Z">Zhenghao Wu</a>, <a href="/search/physics?searchtype=author&query=Wang%2C+W">Wujie Wang</a>, <a href="/search/physics?searchtype=author&query=Xie%2C+T">Tian Xie</a>, <a href="/search/physics?searchtype=author&query=Keten%2C+S">Sinan Keten</a>, <a href="/search/physics?searchtype=author&query=Gomez-Bombarelli%2C+R">Rafael Gomez-Bombarelli</a>, <a href="/search/physics?searchtype=author&query=Jaakkola%2C+T">Tommi Jaakkola</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="2210.07237v2-abstract-short" style="display: inline;"> Molecular dynamics (MD) simulation techniques are widely used for various natural science applications. Increasingly, machine learning (ML) force field (FF) models begin to replace ab-initio simulations by predicting forces directly from atomic structures. Despite significant progress in this area, such techniques are primarily benchmarked by their force/energy prediction errors, even though the p… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.07237v2-abstract-full').style.display = 'inline'; document.getElementById('2210.07237v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2210.07237v2-abstract-full" style="display: none;"> Molecular dynamics (MD) simulation techniques are widely used for various natural science applications. Increasingly, machine learning (ML) force field (FF) models begin to replace ab-initio simulations by predicting forces directly from atomic structures. Despite significant progress in this area, such techniques are primarily benchmarked by their force/energy prediction errors, even though the practical use case would be to produce realistic MD trajectories. We aim to fill this gap by introducing a novel benchmark suite for learned MD simulation. We curate representative MD systems, including water, organic molecules, a peptide, and materials, and design evaluation metrics corresponding to the scientific objectives of respective systems. We benchmark a collection of state-of-the-art (SOTA) ML FF models and illustrate, in particular, how the commonly benchmarked force accuracy is not well aligned with relevant simulation metrics. We demonstrate when and how selected SOTA methods fail, along with offering directions for further improvement. Specifically, we identify stability as a key metric for ML models to improve. Our benchmark suite comes with a comprehensive open-source codebase for training and simulation with ML FFs to facilitate future work. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2210.07237v2-abstract-full').style.display = 'none'; document.getElementById('2210.07237v2-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, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 13 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">31 pages, 18 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Transactions on Machine Learning Research, 2023 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2208.14913">arXiv:2208.14913</a> <span> [<a href="https://arxiv.org/pdf/2208.14913">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1063/5.0106414">10.1063/5.0106414 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Perpendicular magnetic anisotropy in as-deposited CoFeB/MgO thin films </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Lou%2C+K">Kaihua Lou</a>, <a href="/search/physics?searchtype=author&query=Xie%2C+T">Tunan Xie</a>, <a href="/search/physics?searchtype=author&query=Zhao%2C+Q">Qianwen Zhao</a>, <a href="/search/physics?searchtype=author&query=Jiang%2C+B">Baiqing Jiang</a>, <a href="/search/physics?searchtype=author&query=Xia%2C+C">ChaoChao Xia</a>, <a href="/search/physics?searchtype=author&query=Zhang%2C+H">Hanying Zhang</a>, <a href="/search/physics?searchtype=author&query=Yao%2C+Z">Zhihong Yao</a>, <a href="/search/physics?searchtype=author&query=Bi%2C+C">Chong Bi</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="2208.14913v1-abstract-short" style="display: inline;"> Fabrication of perpendicularly magnetized ferromagnetic films on various buffer layers, especially on numerous newly discovered spin-orbit torque (SOT) materials to construct energy-efficient spin-orbitronic devices, is a long-standing challenge. Even for the widely used CoFeB/MgO structures, perpendicular magnetic anisotropy (PMA) can only be established on limited buffer layers through post-anne… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.14913v1-abstract-full').style.display = 'inline'; document.getElementById('2208.14913v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2208.14913v1-abstract-full" style="display: none;"> Fabrication of perpendicularly magnetized ferromagnetic films on various buffer layers, especially on numerous newly discovered spin-orbit torque (SOT) materials to construct energy-efficient spin-orbitronic devices, is a long-standing challenge. Even for the widely used CoFeB/MgO structures, perpendicular magnetic anisotropy (PMA) can only be established on limited buffer layers through post-annealing above 300 掳C. Here, we report that the PMA of CoFeB/MgO films can be established reliably on various buffer layers in the absence of post-annealing. Further results show that precise control of MgO thickness, which determines oxygen diffusion in the underneath CoFeB layer, is the key to obtaining the as-deposited PMA. Interestingly, contrary to previous understanding, post-annealing does not influence the well-established as-deposited PMA significantly but indeed enhances unsaturated PMA with a thick MgO layer by modulating oxygen distributions, rather than crystallinity or Co- and Fe-O bonding. Moreover, our results indicate that oxygen diffusion also plays a critical role in the PMA degradation at high temperature. These results provide a practical approach to build spin-orbitronic devices based on various high-efficient SOT materials. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.14913v1-abstract-full').style.display = 'none'; document.getElementById('2208.14913v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 31 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">15 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/2208.01692">arXiv:2208.01692</a> <span> [<a href="https://arxiv.org/pdf/2208.01692">pdf</a>, <a href="https://arxiv.org/format/2208.01692">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Artificial Intelligence">cs.AI</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Machine Learning">cs.LG</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"> A cloud platform for automating and sharing analysis of raw simulation data from high throughput polymer molecular dynamics simulations </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Xie%2C+T">Tian Xie</a>, <a href="/search/physics?searchtype=author&query=Kwon%2C+H">Ha-Kyung Kwon</a>, <a href="/search/physics?searchtype=author&query=Schweigert%2C+D">Daniel Schweigert</a>, <a href="/search/physics?searchtype=author&query=Gong%2C+S">Sheng Gong</a>, <a href="/search/physics?searchtype=author&query=France-Lanord%2C+A">Arthur France-Lanord</a>, <a href="/search/physics?searchtype=author&query=Khajeh%2C+A">Arash Khajeh</a>, <a href="/search/physics?searchtype=author&query=Crabb%2C+E">Emily Crabb</a>, <a href="/search/physics?searchtype=author&query=Puzon%2C+M">Michael Puzon</a>, <a href="/search/physics?searchtype=author&query=Fajardo%2C+C">Chris Fajardo</a>, <a href="/search/physics?searchtype=author&query=Powelson%2C+W">Will Powelson</a>, <a href="/search/physics?searchtype=author&query=Shao-Horn%2C+Y">Yang Shao-Horn</a>, <a href="/search/physics?searchtype=author&query=Grossman%2C+J+C">Jeffrey C. Grossman</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="2208.01692v1-abstract-short" style="display: inline;"> Open material databases storing hundreds of thousands of material structures and their corresponding properties have become the cornerstone of modern computational materials science. Yet, the raw outputs of the simulations, such as the trajectories from molecular dynamics simulations and charge densities from density functional theory calculations, are generally not shared due to their huge size.… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.01692v1-abstract-full').style.display = 'inline'; document.getElementById('2208.01692v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2208.01692v1-abstract-full" style="display: none;"> Open material databases storing hundreds of thousands of material structures and their corresponding properties have become the cornerstone of modern computational materials science. Yet, the raw outputs of the simulations, such as the trajectories from molecular dynamics simulations and charge densities from density functional theory calculations, are generally not shared due to their huge size. In this work, we describe a cloud-based platform to facilitate the sharing of raw data and enable the fast post-processing in the cloud to extract new properties defined by the user. As an initial demonstration, our database currently includes 6286 molecular dynamics trajectories for amorphous polymer electrolytes and 5.7 terabytes of data. We create a public analysis library at https://github.com/TRI-AMDD/htp_md to extract multiple properties from the raw data, using both expert designed functions and machine learning models. The analysis is run automatically with computation in the cloud, and results then populate a database that can be accessed publicly. Our platform encourages users to contribute both new trajectory data and analysis functions via public interfaces. Newly analyzed properties will be incorporated into the database. Finally, we create a front-end user interface at https://www.htpmd.matr.io for browsing and visualization of our data. We envision the platform to be a new way of sharing raw data and new insights for the computational materials science community. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.01692v1-abstract-full').style.display = 'none'; document.getElementById('2208.01692v1-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 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">21 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/2208.01459">arXiv:2208.01459</a> <span> [<a href="https://arxiv.org/pdf/2208.01459">pdf</a>, <a href="https://arxiv.org/format/2208.01459">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="Pattern Formation and Solitons">nlin.PS</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/lpor.202200487">10.1002/lpor.202200487 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Observation of SQUID-like behavior in fiber laser with intra-cavity epsilon-near-zero effect </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Wu%2C+J">Jiaye Wu</a>, <a href="/search/physics?searchtype=author&query=Liu%2C+X">Xuanyi Liu</a>, <a href="/search/physics?searchtype=author&query=Malomed%2C+B+A">Boris A. Malomed</a>, <a href="/search/physics?searchtype=author&query=Chang%2C+K">Kuan-Chang Chang</a>, <a href="/search/physics?searchtype=author&query=Zhao%2C+M">Minghe Zhao</a>, <a href="/search/physics?searchtype=author&query=Qi%2C+K">Kang Qi</a>, <a href="/search/physics?searchtype=author&query=Sha%2C+Y">Yanhua Sha</a>, <a href="/search/physics?searchtype=author&query=Xie%2C+Z+T">Ze Tao Xie</a>, <a href="/search/physics?searchtype=author&query=Clementi%2C+M">Marco Clementi</a>, <a href="/search/physics?searchtype=author&query=Br%C3%A8s%2C+C">Camille-Sophie Br猫s</a>, <a href="/search/physics?searchtype=author&query=Zhang%2C+S">Shengdong Zhang</a>, <a href="/search/physics?searchtype=author&query=Fu%2C+H+Y">H. Y. Fu</a>, <a href="/search/physics?searchtype=author&query=Li%2C+Q">Qian Li</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="2208.01459v1-abstract-short" style="display: inline;"> Establishing relations between fundamental effects in far-flung areas of physics is a subject of great interest in the current research. We here report realization of a novel photonic system akin to the radio-frequency superconducting quantum interference device (RF-SQUID), in a fiber laser cavity with epsilon-near-zero (ENZ) nanolayers as intra-cavity components. Emulating the RF-SQUID scheme, th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.01459v1-abstract-full').style.display = 'inline'; document.getElementById('2208.01459v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2208.01459v1-abstract-full" style="display: none;"> Establishing relations between fundamental effects in far-flung areas of physics is a subject of great interest in the current research. We here report realization of a novel photonic system akin to the radio-frequency superconducting quantum interference device (RF-SQUID), in a fiber laser cavity with epsilon-near-zero (ENZ) nanolayers as intra-cavity components. Emulating the RF-SQUID scheme, the photonic counterpart of the supercurrent, represented by the optical wave, circulates in the cavity, passing through effective optical potential barriers. Different ENZ wavelengths translate into distinct spectral outputs through the variation of cavity resonances, emulating the situation with a frequency-varying tank circuit in the RF-SQUID. Due to the presence of the ENZ element, the optical potential barrier is far lower for selected frequency components, granting them advantage in the gain-resource competition. The findings reported in this work provide a deeper insight into the ultrafast ENZ photonics, revealing a new path towards the design of nanophotonic on-chip devices with various operational functions, and offer a new approach to study superconducting and quantum-mechanical systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2208.01459v1-abstract-full').style.display = 'none'; document.getElementById('2208.01459v1-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 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">to be published in Laser & Photonics Reviews</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2204.10348">arXiv:2204.10348</a> <span> [<a href="https://arxiv.org/pdf/2204.10348">pdf</a>, <a href="https://arxiv.org/format/2204.10348">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Machine Learning">cs.LG</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"> Simulate Time-integrated Coarse-grained Molecular Dynamics with Multi-Scale Graph Networks </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Fu%2C+X">Xiang Fu</a>, <a href="/search/physics?searchtype=author&query=Xie%2C+T">Tian Xie</a>, <a href="/search/physics?searchtype=author&query=Rebello%2C+N+J">Nathan J. Rebello</a>, <a href="/search/physics?searchtype=author&query=Olsen%2C+B+D">Bradley D. Olsen</a>, <a href="/search/physics?searchtype=author&query=Jaakkola%2C+T">Tommi Jaakkola</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="2204.10348v3-abstract-short" style="display: inline;"> Molecular dynamics (MD) simulation is essential for various scientific domains but computationally expensive. Learning-based force fields have made significant progress in accelerating ab-initio MD simulation but are not fast enough for many real-world applications due to slow inference for large systems and small time steps (femtosecond-level). We aim to address these challenges by learning a mul… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.10348v3-abstract-full').style.display = 'inline'; document.getElementById('2204.10348v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2204.10348v3-abstract-full" style="display: none;"> Molecular dynamics (MD) simulation is essential for various scientific domains but computationally expensive. Learning-based force fields have made significant progress in accelerating ab-initio MD simulation but are not fast enough for many real-world applications due to slow inference for large systems and small time steps (femtosecond-level). We aim to address these challenges by learning a multi-scale graph neural network that directly simulates coarse-grained MD with a very large time step (nanosecond-level) and a novel refinement module based on diffusion models to mitigate simulation instability. The effectiveness of our method is demonstrated in two complex systems: single-chain coarse-grained polymers and multi-component Li-ion polymer electrolytes. For evaluation, we simulate trajectories much longer than the training trajectories for systems with different chemical compositions that the model is not trained on. Structural and dynamical properties can be accurately recovered at several orders of magnitude higher speed than classical force fields by getting out of the femtosecond regime. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2204.10348v3-abstract-full').style.display = 'none'; document.getElementById('2204.10348v3-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, 2023; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 21 April, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 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">27 pages, 16 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Transactions on Machine Learning Research, 2023 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2203.08346">arXiv:2203.08346</a> <span> [<a href="https://arxiv.org/pdf/2203.08346">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Plasma Physics">physics.plasm-ph</span> </div> </div> <p class="title is-5 mathjax"> On the drift wave eigenmode crossing zero frequency in Tokamak </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Liu%2C+Z+Y">Z. Y. Liu</a>, <a href="/search/physics?searchtype=author&query=Zhang%2C+Y+Z">Y. Z. Zhang</a>, <a href="/search/physics?searchtype=author&query=Mahajan%2C+S+M">S. M. Mahajan</a>, <a href="/search/physics?searchtype=author&query=Xie%2C+T">T. Xie</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="2203.08346v1-abstract-short" style="display: inline;"> The conventional ion temperature gradient or 畏_i mode is known to propagate in the ion diamagnetic direction. Investigation of a generic drift fluid model with warm ions and adiabatic electrons, reveals that as 畏_i decreases, the propagation characteristics of the unstable mode may change drastically, the mode frequency first decreases in magnitude, and reaches zero for a critical 畏_i. But as 畏_i… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.08346v1-abstract-full').style.display = 'inline'; document.getElementById('2203.08346v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2203.08346v1-abstract-full" style="display: none;"> The conventional ion temperature gradient or 畏_i mode is known to propagate in the ion diamagnetic direction. Investigation of a generic drift fluid model with warm ions and adiabatic electrons, reveals that as 畏_i decreases, the propagation characteristics of the unstable mode may change drastically, the mode frequency first decreases in magnitude, and reaches zero for a critical 畏_i. But as 畏_i goes down further, the mode begins to propagate in the electron diamagnetic direction. The lower toroidal mode number perturbations are more prone to reversal in propagation direction. Even for 畏_i=0, the mode remains unstable, drawing free energy form the density gradients. Since finite ion temperature appears to be essential for propagation in the electron direction, it is appropriate to introduce new terminology and call this wave the warm ion electron drift (WIED) mode. The model drift wave system is explored within the framework of the two dimensional (2D) weakly asymmetric ballooning theory (WABT) for local eigenmode satisfying natural boundary conditions. The physics behind the excitation of the eigenmode crossing zero frequency is identified to be the reactive instability induced by the curvature coupling between the positive energy wave and the negative energy wave, a damped mode in electron direction coupled to a growing mode in the ion direction in non-dissipative slab limit. Apart from its intrinsic scientific value, this mechanism may shed some light onto the nature of tokamak edge turbulence observed in frequencies moderately lower than the electron diamagnetic frequency; understanding this phenomenon could be helpful in conceptual design around the edge region of future tokamak. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2203.08346v1-abstract-full').style.display = 'none'; document.getElementById('2203.08346v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 15 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> March 2022. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2201.09059">arXiv:2201.09059</a> <span> [<a href="https://arxiv.org/pdf/2201.09059">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"> High-throughput calculations combining machine learning to investigate the corrosion properties of binary Mg alloys </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Wang%2C+Y">Yaowei Wang</a>, <a href="/search/physics?searchtype=author&query=Xie%2C+T">Tian Xie</a>, <a href="/search/physics?searchtype=author&query=Tang%2C+Q">Qingli Tang</a>, <a href="/search/physics?searchtype=author&query=Wang%2C+M">Mingxu Wang</a>, <a href="/search/physics?searchtype=author&query=Ying%2C+T">Tao Ying</a>, <a href="/search/physics?searchtype=author&query=Zhu%2C+H">Hong Zhu</a>, <a href="/search/physics?searchtype=author&query=Zeng%2C+X">Xiaoqin Zeng</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2201.09059v1-abstract-short" style="display: inline;"> Magnesium (Mg) alloys have shown great prospects as both structural and biomedical materials, while poor corrosion resistance limits their further application. In this work, to avoid the time-consuming and laborious experiment trial, a high-throughput computational strategy based on first-principles calculations is designed for screening corrosion-resistant binary Mg alloy with intermetallics, fro… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2201.09059v1-abstract-full').style.display = 'inline'; document.getElementById('2201.09059v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2201.09059v1-abstract-full" style="display: none;"> Magnesium (Mg) alloys have shown great prospects as both structural and biomedical materials, while poor corrosion resistance limits their further application. In this work, to avoid the time-consuming and laborious experiment trial, a high-throughput computational strategy based on first-principles calculations is designed for screening corrosion-resistant binary Mg alloy with intermetallics, from both the thermodynamic and kinetic perspectives. The stable binary Mg intermetallics with low equilibrium potential difference with respect to the Mg matrix are firstly identified. Then, the hydrogen adsorption energies on the surfaces of these Mg intermetallics are calculated, and the corrosion exchange current density is further calculated by a hydrogen evolution reaction (HER) kinetic model. Several intermetallics, e.g. Y3Mg, Y2Mg and La5Mg, are identified to be promising intermetallics which might effectively hinder the cathodic HER. Furthermore, machine learning (ML) models are developed to predict Mg intermetallics with proper hydrogen adsorption energy employing work function (W_f) and weighted first ionization energy (WFIE). The generalization of the ML models is tested on five new binary Mg intermetallics with the average root mean square error (RMSE) of 0.11 eV. This study not only predicts some promising binary Mg intermetallics which may suppress the galvanic corrosion, but also provides a high-throughput screening strategy and ML models for the design of corrosion-resistant alloy, which can be extended to ternary Mg alloys or other alloy systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2201.09059v1-abstract-full').style.display = 'none'; document.getElementById('2201.09059v1-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 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">23 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/2110.06197">arXiv:2110.06197</a> <span> [<a href="https://arxiv.org/pdf/2110.06197">pdf</a>, <a href="https://arxiv.org/format/2110.06197">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Machine Learning">cs.LG</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="Computational Physics">physics.comp-ph</span> </div> </div> <p class="title is-5 mathjax"> Crystal Diffusion Variational Autoencoder for Periodic Material Generation </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Xie%2C+T">Tian Xie</a>, <a href="/search/physics?searchtype=author&query=Fu%2C+X">Xiang Fu</a>, <a href="/search/physics?searchtype=author&query=Ganea%2C+O">Octavian-Eugen Ganea</a>, <a href="/search/physics?searchtype=author&query=Barzilay%2C+R">Regina Barzilay</a>, <a href="/search/physics?searchtype=author&query=Jaakkola%2C+T">Tommi Jaakkola</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="2110.06197v3-abstract-short" style="display: inline;"> Generating the periodic structure of stable materials is a long-standing challenge for the material design community. This task is difficult because stable materials only exist in a low-dimensional subspace of all possible periodic arrangements of atoms: 1) the coordinates must lie in the local energy minimum defined by quantum mechanics, and 2) global stability also requires the structure to foll… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2110.06197v3-abstract-full').style.display = 'inline'; document.getElementById('2110.06197v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2110.06197v3-abstract-full" style="display: none;"> Generating the periodic structure of stable materials is a long-standing challenge for the material design community. This task is difficult because stable materials only exist in a low-dimensional subspace of all possible periodic arrangements of atoms: 1) the coordinates must lie in the local energy minimum defined by quantum mechanics, and 2) global stability also requires the structure to follow the complex, yet specific bonding preferences between different atom types. Existing methods fail to incorporate these factors and often lack proper invariances. We propose a Crystal Diffusion Variational Autoencoder (CDVAE) that captures the physical inductive bias of material stability. By learning from the data distribution of stable materials, the decoder generates materials in a diffusion process that moves atomic coordinates towards a lower energy state and updates atom types to satisfy bonding preferences between neighbors. Our model also explicitly encodes interactions across periodic boundaries and respects permutation, translation, rotation, and periodic invariances. We significantly outperform past methods in three tasks: 1) reconstructing the input structure, 2) generating valid, diverse, and realistic materials, and 3) generating materials that optimize a specific property. We also provide several standard datasets and evaluation metrics for the broader machine learning community. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2110.06197v3-abstract-full').style.display = 'none'; document.getElementById('2110.06197v3-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 14 March, 2022; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 12 October, 2021; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 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 to ICLR 2022. Code and data are publicly available at https://github.com/txie-93/cdvae</span> </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2104.01501">arXiv:2104.01501</a> <span> [<a href="https://arxiv.org/pdf/2104.01501">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</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="Atomic Physics">physics.atom-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/PhysRevB.104.054111">10.1103/PhysRevB.104.054111 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Characterization of Er$^{3+}$:YVO$_{4}$ for microwave to optical transduction </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Xie%2C+T">Tian Xie</a>, <a href="/search/physics?searchtype=author&query=Rochman%2C+J">Jake Rochman</a>, <a href="/search/physics?searchtype=author&query=Bartholomew%2C+J+G">John G. Bartholomew</a>, <a href="/search/physics?searchtype=author&query=Ruskuc%2C+A">Andrei Ruskuc</a>, <a href="/search/physics?searchtype=author&query=Kindem%2C+J+M">Jonathan M. Kindem</a>, <a href="/search/physics?searchtype=author&query=Craiciu%2C+I">Ioana Craiciu</a>, <a href="/search/physics?searchtype=author&query=Thiel%2C+C">Charles Thiel</a>, <a href="/search/physics?searchtype=author&query=Cone%2C+R">Rufus Cone</a>, <a href="/search/physics?searchtype=author&query=Faraon%2C+A">Andrei Faraon</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="2104.01501v1-abstract-short" style="display: inline;"> Quantum transduction between microwave and optical frequencies is important for connecting superconducting quantum platforms in a quantum network. Ensembles of rare-earth ions are promising candidates to achieve this conversion due to their collective coherent properties at microwave and optical frequencies. Erbium ions are of particular interest because of their telecom wavelength optical transit… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.01501v1-abstract-full').style.display = 'inline'; document.getElementById('2104.01501v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2104.01501v1-abstract-full" style="display: none;"> Quantum transduction between microwave and optical frequencies is important for connecting superconducting quantum platforms in a quantum network. Ensembles of rare-earth ions are promising candidates to achieve this conversion due to their collective coherent properties at microwave and optical frequencies. Erbium ions are of particular interest because of their telecom wavelength optical transitions that are compatible with fiber communication networks. Here, we report the optical and electron spin properties of erbium doped yttrium orthovanadate (Er$^{3+}$:YVO$_{4}$), including high-resolution optical spectroscopy, electron paramagnetic resonance studies and an initial demonstration of microwave to optical conversion of classical fields. The highly absorptive optical transitions and narrow ensemble linewidths make Er$^{3+}$:YVO$_{4}$ promising for magneto-optic quantum transduction. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2104.01501v1-abstract-full').style.display = 'none'; document.getElementById('2104.01501v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 3 April, 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> Phys. Rev. B 104, 054111 (2021) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/2007.00252">arXiv:2007.00252</a> <span> [<a href="https://arxiv.org/pdf/2007.00252">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Plasma Physics">physics.plasm-ph</span> </div> </div> <p class="title is-5 mathjax"> The intermittent excitation of geodesic acoustic mode by nonlinear Instanton of electron drift wave envelope in L-mode discharge near tokamak edge </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Liu%2C+Z+Y">Z. Y. Liu</a>, <a href="/search/physics?searchtype=author&query=Zhang%2C+Y+Z">Y. Z. Zhang</a>, <a href="/search/physics?searchtype=author&query=Mahajan%2C+S+M">S. M. Mahajan</a>, <a href="/search/physics?searchtype=author&query=Liu%2C+A+D">A. D. Liu</a>, <a href="/search/physics?searchtype=author&query=Zhou%2C+C">C. Zhou</a>, <a href="/search/physics?searchtype=author&query=Xie%2C+T">T. Xie</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="2007.00252v3-abstract-short" style="display: inline;"> There are two distinct phases in the evolution of drift wave envelope in the presence of zonal flow. A long-lived standing wave phase, which we call the Caviton, and a short-lived traveling wave phase (in radial direction) we call the Instanton. For drift wave turbulence driven by ion temperature gradient mode (ITG), these two stages of dynamics were displayed in [Zhang Y Z, Liu Z Y, Xie T, Mahaja… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2007.00252v3-abstract-full').style.display = 'inline'; document.getElementById('2007.00252v3-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2007.00252v3-abstract-full" style="display: none;"> There are two distinct phases in the evolution of drift wave envelope in the presence of zonal flow. A long-lived standing wave phase, which we call the Caviton, and a short-lived traveling wave phase (in radial direction) we call the Instanton. For drift wave turbulence driven by ion temperature gradient mode (ITG), these two stages of dynamics were displayed in [Zhang Y Z, Liu Z Y, Xie T, Mahajan S M and Liu J 2017 Physics of Plasmas 24 122304]. In this paper we show that the dynamical attributes of ITG turbulence are readily replicated when the turbulence rotates in the electron direction; our model calculation deals specifically with the toroidal electron drift waves (EDW) in the well-known 未_e model. While the basic calculations are presented in parallel to the ITG counterpart, more emphasis is laid here on the motion of Instanton; several abrupt phenomena observed in tokamaks, such as intermittent excitation of geodesic acoustic mode (GAM) shown in this paper, could be attributed to the sudden and fast radial motion of Instanton. The calculation brings out the defining characteristics of the Instanton: it begins as a linear traveling wave right after the transition. Then, it evolves to a nonlinear stage with increasing frequency all the way to 20 kHz. The modulation to Reynolds stress in zonal flow equation will cause resonant excitation to GAM. The intermittency is shown due to the random phase mixing between multiple central rational surfaces in the reaction region. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2007.00252v3-abstract-full').style.display = 'none'; document.getElementById('2007.00252v3-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 March, 2021; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 1 July, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">54 pages, 19 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/2007.00250">arXiv:2007.00250</a> <span> [<a href="https://arxiv.org/pdf/2007.00250">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Plasma Physics">physics.plasm-ph</span> </div> </div> <p class="title is-5 mathjax"> The theoretical study on intermittency and propagation of geodesic acoustic mode in L- mode discharge near tokamak edge </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Liu%2C+Z">Zhaoyang Liu</a>, <a href="/search/physics?searchtype=author&query=Zhang%2C+Y">Yangzhong Zhang</a>, <a href="/search/physics?searchtype=author&query=Mahajan%2C+S+M">Swadesh Mitter Mahajan</a>, <a href="/search/physics?searchtype=author&query=Liu%2C+A">Adi Liu</a>, <a href="/search/physics?searchtype=author&query=Xie%2C+T">Tao Xie</a>, <a href="/search/physics?searchtype=author&query=Zhou%2C+C">Chu Zhou</a>, <a href="/search/physics?searchtype=author&query=Lan%2C+T">Tao Lan</a>, <a href="/search/physics?searchtype=author&query=Xie%2C+J">Jinlin Xie</a>, <a href="/search/physics?searchtype=author&query=Li%2C+H">Hong Li</a>, <a href="/search/physics?searchtype=author&query=Zhuang%2C+G">Ge Zhuang</a>, <a href="/search/physics?searchtype=author&query=Liu%2C+W">Wandong Liu</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="2007.00250v2-abstract-short" style="display: inline;"> Through a systematically developed theory, we demonstrate that the motion of instanton identified in [Y. Z. Zhang, Z. Y. Liu, T. Xie, S. M. Mahajan, and J. Liu, Physics of Plasmas 24, 122304 (2017)] is highly correlated to the intermittent excitation and propagation of geodesic acoustic mode (GAM) that are observed in tokamaks. While many numerical simulations have observed the phenomena, it is th… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2007.00250v2-abstract-full').style.display = 'inline'; document.getElementById('2007.00250v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2007.00250v2-abstract-full" style="display: none;"> Through a systematically developed theory, we demonstrate that the motion of instanton identified in [Y. Z. Zhang, Z. Y. Liu, T. Xie, S. M. Mahajan, and J. Liu, Physics of Plasmas 24, 122304 (2017)] is highly correlated to the intermittent excitation and propagation of geodesic acoustic mode (GAM) that are observed in tokamaks. While many numerical simulations have observed the phenomena, it is the first theory that reveals the physical mechanism behind GAM intermittent excitation and propagation. The preceding work is based on the micro-turbulence associated with toroidal ion temperature gradient (ITG) mode, and slab-based phenomenological model of zonal flow. When full toroidal effect are introduced into the system, two branches of zonal flow emerge: the torus-modified low frequency zonal flow (TLFZF), and GAM, necessitating a unified exploration of GAM and TLFZF. Indeed, we observe that the transition (decay) from the caviton to instanton is triggered by a rapid zero-crossing of radial group velocity of drift wave and is found to be strongly correlated with the GAM onset. Many features peculiar to intermittent GAMs, observed in real machines, are thus identified in the numerical experiment. The results will be displayed in figures and in a movie; first for single central rational surface, and then with coupled multiple central rational surfaces. The periodic bursting first shown disappears as being replaced by irregular one, more similar to the intermittent characteristics observed in GAM experiments. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2007.00250v2-abstract-full').style.display = 'none'; document.getElementById('2007.00250v2-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 October, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 1 July, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">51 pages, 13 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/2006.09014">arXiv:2006.09014</a> <span> [<a href="https://arxiv.org/pdf/2006.09014">pdf</a>, <a href="https://arxiv.org/ps/2006.09014">ps</a>, <a href="https://arxiv.org/format/2006.09014">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Gases">cond-mat.quant-gas</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-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.125.153202">10.1103/PhysRevLett.125.153202 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Optical shielding of destructive chemical reactions between ultracold ground-state NaRb molecules </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Xie%2C+T">T. Xie</a>, <a href="/search/physics?searchtype=author&query=Lepers%2C+M">M. Lepers</a>, <a href="/search/physics?searchtype=author&query=Vexiau%2C+R">R. Vexiau</a>, <a href="/search/physics?searchtype=author&query=Orban%2C+A">A. Orban</a>, <a href="/search/physics?searchtype=author&query=Dulieu%2C+O">O. Dulieu</a>, <a href="/search/physics?searchtype=author&query=Bouloufa-Maafa%2C+N">N. Bouloufa-Maafa</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="2006.09014v2-abstract-short" style="display: inline;"> We propose a method to suppress the chemical reactions between ultracold bosonic ground-state $^{23}$Na$^{87}$Rb molecules based on optical shielding. By applying a laser with a frequency blue-detuned from the transition between the lowest rovibrational level of the electronic ground state $X^1危^+ (v_X=0, j_X=0)$, and the long-lived excited level $b^3螤_0 (v_b=0, j_b=1)$, the long-range dipole-dipo… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2006.09014v2-abstract-full').style.display = 'inline'; document.getElementById('2006.09014v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="2006.09014v2-abstract-full" style="display: none;"> We propose a method to suppress the chemical reactions between ultracold bosonic ground-state $^{23}$Na$^{87}$Rb molecules based on optical shielding. By applying a laser with a frequency blue-detuned from the transition between the lowest rovibrational level of the electronic ground state $X^1危^+ (v_X=0, j_X=0)$, and the long-lived excited level $b^3螤_0 (v_b=0, j_b=1)$, the long-range dipole-dipole interaction between the colliding molecules can be engineered, leading to a dramatic suppression of reactive and photoinduced inelastic collisions, for both linear and circular laser polarizations. We demonstrate that the spontaneous emission from $b^3螤_0 (v_b=0, j_b=1)$ does not deteriorate the shielding process. This opens the possibility for a strong increase of the lifetime of cold molecule traps, and for an efficient evaporative cooling. We also anticipate that the proposed mechanism is valid for alkali-metal diatomics with sufficiently large dipole-dipole interactions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('2006.09014v2-abstract-full').style.display = 'none'; document.getElementById('2006.09014v2-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 August, 2020; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 16 June, 2020; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2020. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. Lett. 125, 153202 (2020) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1912.03671">arXiv:1912.03671</a> <span> [<a href="https://arxiv.org/pdf/1912.03671">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Physics">quant-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41467-020-16996-x">10.1038/s41467-020-16996-x <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> On-chip coherent microwave-to-optical transduction mediated by ytterbium in YVO$_4$ </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Bartholomew%2C+J+G">John G. Bartholomew</a>, <a href="/search/physics?searchtype=author&query=Rochman%2C+J">Jake Rochman</a>, <a href="/search/physics?searchtype=author&query=Xie%2C+T">Tian Xie</a>, <a href="/search/physics?searchtype=author&query=Kindem%2C+J+M">Jonathan M. Kindem</a>, <a href="/search/physics?searchtype=author&query=Ruskuc%2C+A">Andrei Ruskuc</a>, <a href="/search/physics?searchtype=author&query=Craiciu%2C+I">Ioana Craiciu</a>, <a href="/search/physics?searchtype=author&query=Lei%2C+M">Mi Lei</a>, <a href="/search/physics?searchtype=author&query=Faraon%2C+A">Andrei Faraon</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="1912.03671v1-abstract-short" style="display: inline;"> Optical networks that distribute entanglement among quantum technologies will form a powerful backbone for quantum science but are yet to interface with leading quantum hardware such as superconducting qubits. Consequently, these systems remain isolated because microwave links at room temperature are noisy and lossy. Building connectivity requires interfaces that map quantum information between mi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1912.03671v1-abstract-full').style.display = 'inline'; document.getElementById('1912.03671v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1912.03671v1-abstract-full" style="display: none;"> Optical networks that distribute entanglement among quantum technologies will form a powerful backbone for quantum science but are yet to interface with leading quantum hardware such as superconducting qubits. Consequently, these systems remain isolated because microwave links at room temperature are noisy and lossy. Building connectivity requires interfaces that map quantum information between microwave and optical fields. While preliminary microwave-to-optical (M2O) transducers have been realized, developing efficient, low-noise devices that match superconducting qubit frequencies (gigahertz) and bandwidths (10 kHz - 1 MHz) remains a challenge. Here we demonstrate a proof-of-concept on-chip M2O transducer using $^{171}\mathrm{Yb}^{3+}$-ions in yttrium orthovanadate (YVO) coupled to a nanophotonic waveguide and a microwave transmission line. The device's miniaturization, material, and zero-magnetic-field operation are important advances for rare-earth ion magneto-optical devices. Further integration with high quality factor microwave and optical resonators will enable efficient transduction and create opportunities toward multi-platform quantum networks. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1912.03671v1-abstract-full').style.display = 'none'; document.getElementById('1912.03671v1-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 December, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2019. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1912.02219">arXiv:1912.02219</a> <span> [<a href="https://arxiv.org/pdf/1912.02219">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Applied Physics">physics.app-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> </div> </div> <p class="title is-5 mathjax"> Strain-Engineered High Responsivity MoTe2 Photodetector for Silicon Photonic Integrated Circuits </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Maiti%2C+R">R. Maiti</a>, <a href="/search/physics?searchtype=author&query=Patil%2C+C">C. Patil</a>, <a href="/search/physics?searchtype=author&query=Xie%2C+T">T. Xie</a>, <a href="/search/physics?searchtype=author&query=Azadani%2C+J+G">J. G. Azadani</a>, <a href="/search/physics?searchtype=author&query=Saadi%2C+M+A+S+R">M. A. S. R. Saadi</a>, <a href="/search/physics?searchtype=author&query=Amin%2C+R">R. Amin</a>, <a href="/search/physics?searchtype=author&query=Miscuglio%2C+M">M. Miscuglio</a>, <a href="/search/physics?searchtype=author&query=Van+Thourhout%2C+D">D. Van Thourhout</a>, <a href="/search/physics?searchtype=author&query=Solares%2C+S+D">S. D. Solares</a>, <a href="/search/physics?searchtype=author&query=Low%2C+T">T. Low</a>, <a href="/search/physics?searchtype=author&query=Agarwal%2C+R">R. Agarwal</a>, <a href="/search/physics?searchtype=author&query=Bank%2C+S">S. Bank</a>, <a href="/search/physics?searchtype=author&query=Sorger%2C+V+J">V. J. Sorger</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="1912.02219v2-abstract-short" style="display: inline;"> In integrated photonics, specific wavelengths are preferred such as 1550 nm due to low-loss transmission and the availability of optical gain in this spectral region. For chip-based photodetectors, layered two-dimensional (2D) materials bear scientific and technologically-relevant properties leading to strong light-matter-interaction devices due to effects such as reduced coulomb screening or exci… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1912.02219v2-abstract-full').style.display = 'inline'; document.getElementById('1912.02219v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1912.02219v2-abstract-full" style="display: none;"> In integrated photonics, specific wavelengths are preferred such as 1550 nm due to low-loss transmission and the availability of optical gain in this spectral region. For chip-based photodetectors, layered two-dimensional (2D) materials bear scientific and technologically-relevant properties leading to strong light-matter-interaction devices due to effects such as reduced coulomb screening or excitonic states. However, no efficient photodetector in the telecommunication C-band using 2D materials has been realized yet. Here, we demonstrate a MoTe2-based photodetector featuring strong photoresponse (responsivity = 0.5 A/W) operating at 1550nm on silicon photonic waveguide enabled by engineering the strain (4%) inside the photo-absorbing transition-metal-dichalcogenide film. We show that an induced tensile strain of ~4% reduces the bandgap of MoTe2 by about 0.2 eV by microscopically measuring the work-function across the device. Unlike Graphene-based photodetectors relying on a gapless band structure, this semiconductor-2D material detector shows a ~100X improved dark current enabling an efficient noise-equivalent power of just 90 pW/Hz^0.5. Such strain-engineered integrated photodetector provides new opportunities for integrated optoelectronic systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1912.02219v2-abstract-full').style.display = 'none'; document.getElementById('1912.02219v2-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 December, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 31 October, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> December 2019. </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1907.10649">arXiv:1907.10649</a> <span> [<a href="https://arxiv.org/pdf/1907.10649">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="Data Analysis, Statistics and Probability">physics.data-an</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.100.184103">10.1103/PhysRevB.100.184103 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Predicting charge density distribution of materials using a local-environment-based graph convolutional network </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Gong%2C+S">Sheng Gong</a>, <a href="/search/physics?searchtype=author&query=Xie%2C+T">Tian Xie</a>, <a href="/search/physics?searchtype=author&query=Zhu%2C+T">Taishan Zhu</a>, <a href="/search/physics?searchtype=author&query=Wang%2C+S">Shuo Wang</a>, <a href="/search/physics?searchtype=author&query=Fadel%2C+E+R">Eric R. Fadel</a>, <a href="/search/physics?searchtype=author&query=Li%2C+Y">Yawei Li</a>, <a href="/search/physics?searchtype=author&query=Grossman%2C+J+C">Jeffrey C. Grossman</a> </p> <p class="abstract mathjax"> <span class="has-text-black-bis has-text-weight-semibold">Abstract</span>: <span class="abstract-short has-text-grey-dark mathjax" id="1907.10649v1-abstract-short" style="display: inline;"> Electron charge density distribution of materials is one of the key quantities in computational materials science as theoretically it determines the ground state energy and practically it is used in many materials analyses. However, the scaling of density functional theory calculations with number of atoms limits the usage of charge-density-based calculations and analyses. Here we introduce a mach… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1907.10649v1-abstract-full').style.display = 'inline'; document.getElementById('1907.10649v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1907.10649v1-abstract-full" style="display: none;"> Electron charge density distribution of materials is one of the key quantities in computational materials science as theoretically it determines the ground state energy and practically it is used in many materials analyses. However, the scaling of density functional theory calculations with number of atoms limits the usage of charge-density-based calculations and analyses. Here we introduce a machine learning scheme with local-environment-based graphs and graph convolutional neural networks to predict charge density on grid-points from crystal structure. We show the accuracy of this scheme through a comparison of predicted charge densities as well as properties derived from the charge density, and the scaling is O(N). More importantly, the transferability is shown to be high with respect to different compositions and structures, which results from the explicit encoding of geometry. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1907.10649v1-abstract-full').style.display = 'none'; document.getElementById('1907.10649v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 24 July, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> July 2019. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. B 100, 184103 (2019) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1902.06836">arXiv:1902.06836</a> <span> [<a href="https://arxiv.org/pdf/1902.06836">pdf</a>, <a href="https://arxiv.org/format/1902.06836">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Machine Learning">cs.LG</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/10.1038/s41467-019-10663-6">10.1038/s41467-019-10663-6 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Graph Dynamical Networks for Unsupervised Learning of Atomic Scale Dynamics in Materials </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Xie%2C+T">Tian Xie</a>, <a href="/search/physics?searchtype=author&query=France-Lanord%2C+A">Arthur France-Lanord</a>, <a href="/search/physics?searchtype=author&query=Wang%2C+Y">Yanming Wang</a>, <a href="/search/physics?searchtype=author&query=Shao-Horn%2C+Y">Yang Shao-Horn</a>, <a href="/search/physics?searchtype=author&query=Grossman%2C+J+C">Jeffrey C. Grossman</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="1902.06836v2-abstract-short" style="display: inline;"> Understanding the dynamical processes that govern the performance of functional materials is essential for the design of next generation materials to tackle global energy and environmental challenges. Many of these processes involve the dynamics of individual atoms or small molecules in condensed phases, e.g. lithium ions in electrolytes, water molecules in membranes, molten atoms at interfaces, e… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1902.06836v2-abstract-full').style.display = 'inline'; document.getElementById('1902.06836v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1902.06836v2-abstract-full" style="display: none;"> Understanding the dynamical processes that govern the performance of functional materials is essential for the design of next generation materials to tackle global energy and environmental challenges. Many of these processes involve the dynamics of individual atoms or small molecules in condensed phases, e.g. lithium ions in electrolytes, water molecules in membranes, molten atoms at interfaces, etc., which are difficult to understand due to the complexity of local environments. In this work, we develop graph dynamical networks, an unsupervised learning approach for understanding atomic scale dynamics in arbitrary phases and environments from molecular dynamics simulations. We show that important dynamical information can be learned for various multi-component amorphous material systems, which is difficult to obtain otherwise. With the large amounts of molecular dynamics data generated everyday in nearly every aspect of materials design, this approach provides a broadly useful, automated tool to understand atomic scale dynamics in material systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1902.06836v2-abstract-full').style.display = 'none'; document.getElementById('1902.06836v2-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 May, 2019; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 18 February, 2019; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 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">25 + 7 pages, 5 + 3 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Nat. Commun. 10, 2667 (2019) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1805.06112">arXiv:1805.06112</a> <span> [<a href="https://arxiv.org/pdf/1805.06112">pdf</a>, <a href="https://arxiv.org/format/1805.06112">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-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/10.1364/JOSAB.36.000243">10.1364/JOSAB.36.000243 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Frequency stabilization of a 650 nm laser to I$_{2}$ spectrum for trapped $^{138}$Ba$^{+}$ ions </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Xie%2C+T">Tian Xie</a>, <a href="/search/physics?searchtype=author&query=Jin%2C+N">Naijun Jin</a>, <a href="/search/physics?searchtype=author&query=Wang%2C+Y">Ye Wang</a>, <a href="/search/physics?searchtype=author&query=Zhang%2C+J">Junhua Zhang</a>, <a href="/search/physics?searchtype=author&query=Um%2C+M">Mark Um</a>, <a href="/search/physics?searchtype=author&query=Wang%2C+P">Pengfei Wang</a>, <a href="/search/physics?searchtype=author&query=Kim%2C+K">Kihwan Kim</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="1805.06112v1-abstract-short" style="display: inline;"> The optical manipulation of Ba$^{+}$ ions is mainly performed by a 493 nm laser for the S$_{1/2}$-P$_{1/2}$ transition and a 650 nm laser for the P$_{1/2}$-D$_{3/2}$ transition. Since the branching ratio between the 493 nm and 650 nm transitions of a single Ba$^{+}$ ion is comparable, stabilization systems of both lasers are equally important for Doppler cooling, sub-Doppler cooling, optical pumpi… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1805.06112v1-abstract-full').style.display = 'inline'; document.getElementById('1805.06112v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1805.06112v1-abstract-full" style="display: none;"> The optical manipulation of Ba$^{+}$ ions is mainly performed by a 493 nm laser for the S$_{1/2}$-P$_{1/2}$ transition and a 650 nm laser for the P$_{1/2}$-D$_{3/2}$ transition. Since the branching ratio between the 493 nm and 650 nm transitions of a single Ba$^{+}$ ion is comparable, stabilization systems of both lasers are equally important for Doppler cooling, sub-Doppler cooling, optical pumping and state detection. The stabilization system of a 493 nm laser to an absolute Te$_2$ reference has been well established. However, the stabilization of a 650 nm laser has not been presented before. Here we report twenty spectral lines of I$_{2}$ in the range of 0.9 GHz above the resonance of the P$_{1/2}$-D$_{3/2}$ transition. We stabilize the 650 nm laser through the optical cavity to the lowest one among these lines, which is about 350 MHz apart, as the absolute frequency reference. Furthermore, we measure the frequency differences between these iodine lines and the Ba$^+$ resonance through fluorescence excitation spectrum with well-resolved dark states, which is in agreement with the theoretical expectation. The presented stabilization scheme enables us to perform precise experiments with Ba$^{+}$ ions. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1805.06112v1-abstract-full').style.display = 'none'; document.getElementById('1805.06112v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 15 May, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2018. </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, 6 figures, 1 table</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> J. Opt. Soc. Am. B 36, 243 (2019) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1805.04206">arXiv:1805.04206</a> <span> [<a href="https://arxiv.org/pdf/1805.04206">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Mesoscale and Nanoscale Physics">cond-mat.mes-hall</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Optics">physics.optics</span> </div> <div class="is-inline-block" style="margin-left: 0.5rem"> <div class="tags has-addons"> <span class="tag is-dark is-size-7">doi</span> <span class="tag is-light is-size-7"><a class="" href="https://doi.org/10.1038/s41467-018-04080-4">10.1038/s41467-018-04080-4 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Chiral Landau levels in Weyl semimetal NbAs with multiple topological carriers </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Yuan%2C+X">Xiang Yuan</a>, <a href="/search/physics?searchtype=author&query=Yan%2C+Z">Zhongbo Yan</a>, <a href="/search/physics?searchtype=author&query=Song%2C+C">Chaoyu Song</a>, <a href="/search/physics?searchtype=author&query=Zhang%2C+M">Mengyao Zhang</a>, <a href="/search/physics?searchtype=author&query=Li%2C+Z">Zhilin Li</a>, <a href="/search/physics?searchtype=author&query=Zhang%2C+C">Cheng Zhang</a>, <a href="/search/physics?searchtype=author&query=Liu%2C+Y">Yanwen Liu</a>, <a href="/search/physics?searchtype=author&query=Wang%2C+W">Weiyi Wang</a>, <a href="/search/physics?searchtype=author&query=Zhao%2C+M">Minhao Zhao</a>, <a href="/search/physics?searchtype=author&query=Lin%2C+Z">Zehao Lin</a>, <a href="/search/physics?searchtype=author&query=Xie%2C+T">Tian Xie</a>, <a href="/search/physics?searchtype=author&query=Ludwig%2C+J">Jonathan Ludwig</a>, <a href="/search/physics?searchtype=author&query=Jiang%2C+Y">Yuxuan Jiang</a>, <a href="/search/physics?searchtype=author&query=Zhang%2C+X">Xiaoxing Zhang</a>, <a href="/search/physics?searchtype=author&query=Shang%2C+C">Cui Shang</a>, <a href="/search/physics?searchtype=author&query=Ye%2C+Z">Zefang Ye</a>, <a href="/search/physics?searchtype=author&query=Wang%2C+J">Jiaxiang Wang</a>, <a href="/search/physics?searchtype=author&query=Chen%2C+F">Feng Chen</a>, <a href="/search/physics?searchtype=author&query=Xia%2C+Z">Zhengcai Xia</a>, <a href="/search/physics?searchtype=author&query=Smirnov%2C+D">Dmitry Smirnov</a>, <a href="/search/physics?searchtype=author&query=Chen%2C+X">Xiaolong Chen</a>, <a href="/search/physics?searchtype=author&query=Wang%2C+Z">Zhong Wang</a>, <a href="/search/physics?searchtype=author&query=Yan%2C+H">Hugen Yan</a>, <a href="/search/physics?searchtype=author&query=Xiu%2C+F">Faxian Xiu</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="1805.04206v1-abstract-short" style="display: inline;"> Recently, Weyl semimetals have been experimentally discovered in both inversion-symmetry-breaking and time-reversal-symmetry-breaking crystals. The non-trivial topology in Weyl semimetals can manifest itself with exotic phenomena which have been extensively investigated by photoemission and transport measurements. Despite the numerous experimental efforts on Fermi arcs and chiral anomaly, the exis… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1805.04206v1-abstract-full').style.display = 'inline'; document.getElementById('1805.04206v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1805.04206v1-abstract-full" style="display: none;"> Recently, Weyl semimetals have been experimentally discovered in both inversion-symmetry-breaking and time-reversal-symmetry-breaking crystals. The non-trivial topology in Weyl semimetals can manifest itself with exotic phenomena which have been extensively investigated by photoemission and transport measurements. Despite the numerous experimental efforts on Fermi arcs and chiral anomaly, the existence of unconventional zeroth Landau levels, as a unique hallmark of Weyl fermions which is highly related to chiral anomaly, remains elusive owing to the stringent experimental requirements. Here, we report the magneto-optical study of Landau quantization in Weyl semimetal NbAs. High magnetic fields drive the system towards the quantum limit which leads to the observation of zeroth chiral Landau levels in two inequivalent Weyl nodes. As compared to other Landau levels, the zeroth chiral Landau level exhibits a distinct linear dispersion in z momentum direction and allows the optical transitions without the limitation of zero z momentum or square root of magnetic field evolution. The magnetic field dependence of the zeroth Landau levels further verifies the predicted particle-hole asymmetry of the Weyl cones. Meanwhile, the optical transitions from the normal Landau levels exhibit the coexistence of multiple carriers including an unexpected massive Dirac fermion, pointing to a more complex topological nature in inversion-symmetry-breaking Weyl semimetals. Our results provide insights into the Landau quantization of Weyl fermions and demonstrate an effective tool for studying complex topological systems. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1805.04206v1-abstract-full').style.display = 'none'; document.getElementById('1805.04206v1-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 May, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> May 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Nature Communications 9,1854 (2018) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1804.04651">arXiv:1804.04651</a> <span> [<a href="https://arxiv.org/pdf/1804.04651">pdf</a>, <a href="https://arxiv.org/format/1804.04651">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Materials Science">cond-mat.mtrl-sci</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Machine Learning">cs.LG</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/acscentsci.8b00229">10.1021/acscentsci.8b00229 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Machine Learning Enabled Computational Screening of Inorganic Solid Electrolytes for Dendrite Suppression with Li Metal Anode </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Ahmad%2C+Z">Zeeshan Ahmad</a>, <a href="/search/physics?searchtype=author&query=Xie%2C+T">Tian Xie</a>, <a href="/search/physics?searchtype=author&query=Maheshwari%2C+C">Chinmay Maheshwari</a>, <a href="/search/physics?searchtype=author&query=Grossman%2C+J+C">Jeffrey C. Grossman</a>, <a href="/search/physics?searchtype=author&query=Viswanathan%2C+V">Venkatasubramanian Viswanathan</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="1804.04651v1-abstract-short" style="display: inline;"> Next generation batteries based on lithium (Li) metal anodes have been plagued by the dendritic electrodeposition of Li metal on the anode during cycling, resulting in short circuit and capacity loss. Suppression of dendritic growth through the use of solid electrolytes has emerged as one of the most promising strategies for enabling the use of Li metal anodes. We perform a computational screening… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1804.04651v1-abstract-full').style.display = 'inline'; document.getElementById('1804.04651v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1804.04651v1-abstract-full" style="display: none;"> Next generation batteries based on lithium (Li) metal anodes have been plagued by the dendritic electrodeposition of Li metal on the anode during cycling, resulting in short circuit and capacity loss. Suppression of dendritic growth through the use of solid electrolytes has emerged as one of the most promising strategies for enabling the use of Li metal anodes. We perform a computational screening of over 12,000 inorganic solids based on their ability to suppress dendrite initiation in contact with Li metal anode. Properties for mechanically isotropic and anisotropic interfaces that can be used in stability criteria for determining the propensity of dendrite initiation are usually obtained from computationally expensive first-principles methods. In order to obtain a large dataset for screening, we use machine learning models to predict the mechanical properties of several new solid electrolytes. We train a convolutional neural network on the shear and bulk moduli purely on structural features of the material. We use AdaBoost, Lasso and Bayesian ridge regression to train the elastic constants, where the choice of the model depended on the size of the training data and the noise that it can handle. Our models give us direct interpretability by revealing the dominant structural features affecting the elastic constants. The stiffness is found to increase with a decrease in volume per atom, increase in minimum anion-anion separation, and increase in sublattice (all but Li) packing fraction. Cross-validation/test performance suggests our models generalize well. We predict over 20 mechanically anisotropic interfaces between Li metal and 6 solid electrolytes which can be used to suppress dendrite growth. Our screened candidates are generally soft and highly anisotropic, and present opportunities for simultaneously obtaining dendrite suppression and high ionic conductivity in solid electrolytes. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1804.04651v1-abstract-full').style.display = 'none'; document.getElementById('1804.04651v1-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, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> April 2018. </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">34 pages, 4 Figures, 3 Table, 7 pages of Supporting Information</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> ACS Cent. Sci., 2018, 4 (8), 996-1006 </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1802.09920">arXiv:1802.09920</a> <span> [<a href="https://arxiv.org/pdf/1802.09920">pdf</a>, <a href="https://arxiv.org/format/1802.09920">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Quantum Gases">cond-mat.quant-gas</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="Atomic Physics">physics.atom-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/PhysRevE.97.050202">10.1103/PhysRevE.97.050202 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Dimensional coupling induced current reversal in two-dimensional driven lattices </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Mukhopadhyay%2C+A+K">Aritra K. Mukhopadhyay</a>, <a href="/search/physics?searchtype=author&query=Xie%2C+T">Tianting Xie</a>, <a href="/search/physics?searchtype=author&query=Liebchen%2C+B">Benno Liebchen</a>, <a href="/search/physics?searchtype=author&query=Schmelcher%2C+P">Peter Schmelcher</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="1802.09920v1-abstract-short" style="display: inline;"> We show that the direction of directed particle transport in a two dimensional ac-driven lattice can be dynamically reversed by changing the structure of the lattice in the direction perpendicular to the applied driving force. These structural changes introduce dimensional coupling effects, the strength of which governs the timescale of the current reversals. The underlying mechanism is based on t… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1802.09920v1-abstract-full').style.display = 'inline'; document.getElementById('1802.09920v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1802.09920v1-abstract-full" style="display: none;"> We show that the direction of directed particle transport in a two dimensional ac-driven lattice can be dynamically reversed by changing the structure of the lattice in the direction perpendicular to the applied driving force. These structural changes introduce dimensional coupling effects, the strength of which governs the timescale of the current reversals. The underlying mechanism is based on the fact that dimensional coupling allows the particles to explore regions of phase space which are inaccessible otherwise. The experimental realization for cold atoms in ac-driven optical lattices is discussed. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1802.09920v1-abstract-full').style.display = 'none'; document.getElementById('1802.09920v1-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 February, 2018; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> February 2018. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. E 97, 050202 (2018) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1606.09441">arXiv:1606.09441</a> <span> [<a href="https://arxiv.org/pdf/1606.09441">pdf</a>, <a href="https://arxiv.org/format/1606.09441">other</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Atomic Physics">physics.atom-ph</span> <span class="tag is-small is-grey tooltip is-tooltip-top" data-tooltip="Quantum Gases">cond-mat.quant-gas</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/PhysRevA.94.023619">10.1103/PhysRevA.94.023619 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> Creating Feshbach resonances for ultracold molecule formation with radiofrequency fields </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Owens%2C+D+J">Daniel J. Owens</a>, <a href="/search/physics?searchtype=author&query=Xie%2C+T">Ting Xie</a>, <a href="/search/physics?searchtype=author&query=Hutson%2C+J+M">Jeremy M. Hutson</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="1606.09441v2-abstract-short" style="display: inline;"> We show that radiofrequency (RF) radiation may be used to create Feshbach resonances in ultracold gases of alkali-metal atoms at desired magnetic fields that are convenient for atomic cooling and degeneracy. For the case of $^{39}$K+$^{133}$Cs, where there are no RF-free resonances in regions where Cs may be cooled to degeneracy, we show that a resonance may be created near 21~G with 69.2~MHz RF r… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1606.09441v2-abstract-full').style.display = 'inline'; document.getElementById('1606.09441v2-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1606.09441v2-abstract-full" style="display: none;"> We show that radiofrequency (RF) radiation may be used to create Feshbach resonances in ultracold gases of alkali-metal atoms at desired magnetic fields that are convenient for atomic cooling and degeneracy. For the case of $^{39}$K+$^{133}$Cs, where there are no RF-free resonances in regions where Cs may be cooled to degeneracy, we show that a resonance may be created near 21~G with 69.2~MHz RF radiation. This resonance is almost lossless with circularly polarized RF, and the molecules created are long-lived even with plane-polarized RF. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1606.09441v2-abstract-full').style.display = 'none'; document.getElementById('1606.09441v2-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 August, 2016; <span class="has-text-black-bis has-text-weight-semibold">v1</span> submitted 30 June, 2016; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> June 2016. </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">Final version. 5 pages, 3 figures</span> </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Journal ref:</span> Phys. Rev. A 94, 023619 (2016) </p> </li> <li class="arxiv-result"> <div class="is-marginless"> <p class="list-title is-inline-block"><a href="https://arxiv.org/abs/1510.00623">arXiv:1510.00623</a> <span> [<a href="https://arxiv.org/pdf/1510.00623">pdf</a>] </span> </p> <div class="tags is-inline-block"> <span class="tag is-small is-link tooltip is-tooltip-top" data-tooltip="Plasma Physics">physics.plasm-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/10.1063/1.4947556">10.1063/1.4947556 <i class="fa fa-external-link" aria-hidden="true"></i></a></span> </div> </div> </div> <p class="title is-5 mathjax"> The unified ballooning theory with weak up-down asymmetric mode structure and the numerical studies </p> <p class="authors"> <span class="search-hit">Authors:</span> <a href="/search/physics?searchtype=author&query=Xie%2C+T">T. Xie</a>, <a href="/search/physics?searchtype=author&query=Qin%2C+H">H. Qin</a>, <a href="/search/physics?searchtype=author&query=Zhang%2C+Y+Z">Y. Z. Zhang</a>, <a href="/search/physics?searchtype=author&query=Mahajan%2C+S+M">S. M. Mahajan</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="1510.00623v1-abstract-short" style="display: inline;"> A unified ballooning theory, constructed on the basis of two special theories [Y. Z. Zhang, S. M. Mahajan, X. D. Zhang, Phys. Fluids B4, 2729 (1992); Y. Z. Zhang, T. Xie, Nucl. Fusion & Plasma Phys. 33, 193 (2013)], shows that a weak up-down asymmetric mode structure is normally formed in an up-down symmetric equilibrium; the weak up-down asymmetry in mode structure is the manifestation of non-tri… <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1510.00623v1-abstract-full').style.display = 'inline'; document.getElementById('1510.00623v1-abstract-short').style.display = 'none';">▽ More</a> </span> <span class="abstract-full has-text-grey-dark mathjax" id="1510.00623v1-abstract-full" style="display: none;"> A unified ballooning theory, constructed on the basis of two special theories [Y. Z. Zhang, S. M. Mahajan, X. D. Zhang, Phys. Fluids B4, 2729 (1992); Y. Z. Zhang, T. Xie, Nucl. Fusion & Plasma Phys. 33, 193 (2013)], shows that a weak up-down asymmetric mode structure is normally formed in an up-down symmetric equilibrium; the weak up-down asymmetry in mode structure is the manifestation of non-trivial higher order effects beyond the standard ballooning equation. It is shown that the asymmetric mode may have even higher growth rate than symmetric modes. Salient features of the theory are illustrated by investigating a fluid model for the ion temperature gradient (ITG) mode. The two dimensional (2D) analytical form of ITG mode, solved in ballooning representation, is then converted into the radial-poloidal space to provide the natural boundary condition for solving the 2D mathematical local eigenmode problem. We find the analytical expression of mode structure in good agreement with finite difference solution. This sets a reliable framework for quasi-linear computation. <a class="is-size-7" style="white-space: nowrap;" onclick="document.getElementById('1510.00623v1-abstract-full').style.display = 'none'; document.getElementById('1510.00623v1-abstract-short').style.display = 'inline';">△ Less</a> </span> </p> <p class="is-size-7"><span class="has-text-black-bis has-text-weight-semibold">Submitted</span> 2 October, 2015; <span class="has-text-black-bis has-text-weight-semibold">originally announced</span> October 2015. </p> <p class="comments is-size-7"> <span class="has-text-black-bis has-text-weight-semibold">Comments:</span> <span class="has-text-grey-dark mathjax">22 pages, 3 figures</span> </p> </li> </ol> <div class="is-hidden-tablet">  <span class="help" style="display: inline-block;"><a href="https://github.com/arXiv/arxiv-search/releases">Search v0.5.6 released 2020-02-24</a>  </span> </div> </div> </main> <footer> <div class="columns is-desktop" role="navigation" 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