Symposium on Quantum Transport and Thermal Energy Science
A Special Series of “NanGaoShi·Physics Online Lecture”
活动时间：
2022年12月3日 (周六) 8:50
主办单位：
南京师范大学物理科学与技术学院
前沿物理与交叉科学研究院
量子输运与热能科学中心
直播通道
蔻享学术直播间
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直播日程
报告人介绍
报告题目：Coulomb-mediated Thermal Energy Transfer Between 2D Electron Systems
Prof. Allan H , MacDonald
The University of Texas at Austin
Allan H. MacDonald is a theoretical condensed matter physicist and the Sid W. Richardson Foundation Regents Chair Professor of Physics at The University of Texas at Austin. MacDonald's research has focused on new or unexplained phenomena related to the quantum physics of interacting electrons in materials. He has contributed to theories of the integer and fractional Quantum Hall effects, spintronics in metals and semiconductors, topological Bloch bands and momentum-space Berry curvature phenomena, etc. His recent work is focused on anticipating new physics in moire superlattices, and on achieving a full understanding of magic-angle bilayer graphene and transition-metal dichalcogenide moire superlattice systems. MacDonald received the Oliver E. Buckley Prize of the American Physical Society in 2007, the Ernst Mach Honorary Medal of the Czech Academy of Sciences in 2012, and the Wolf Prize in Physics in 2020. He was elected to the American Academy of Arts and Sciences in 2005 and the National Academy of the Sciences in 2012.
李保文 讲席教授
南方科大材料系与物理系
李保文，南方科大材料系与物理系，欧洲科学院（Academia Europae）院士, 美国物理学会Fellow。曾任博尔德科罗拉多大学机械工程系/物理系冠名终身教授 （2015-2021），新加坡国立大学终身教授（2000-2015）。声子学和微纳米尺度热输运的领军人才。发表文章380多篇包括3篇Rev Mod. Phys, 30篇PRL。H-指数91，引用超过28000. 曾获2005新加坡国家科学奖，2005海外华人物理理学会亚洲成就奖，2017国际声子学会布理渊奖。指导博士生40多名，博士后40多人。研究领域包括：声子学与量子声子学，热能调控材料和技术，量子传感，经典与量子混沌，复杂网络 报告题目：纳米尺度声子热输运：从基础研究到应用报告摘要：Phonons are carriers of both information and energy. They are main heat carriers in semiconductors and dielectric materials. In this talk, I will answer the following questions: (1) why thermal conductivity in low dimensional materials diverges with system size? (2) What is connection between divergent (anomalous) thermal conductivity and anomalous diffusion? （3）How can we control its transport via interface? (4) Can phonons be condensed and how can we use it?
牛谦 教授
中国科学技术大学
牛谦，1981年毕业于北京大学物理系，1985年获美国华盛顿大学理学博士。1985-1990年分别在University of Illinois（UIUC）和University of California at Santa Barbara（UCSB）做博士后研究。1990年至2021年在美国德克萨斯大学奥斯汀分校工作，历任助理教授、副教授、教授、Trull Centennial教授、Sid W. Richardson Foundation Regents Chair in Physics（2019-2021），2021年10月起任中国科学技术大学教授、杰出讲席教授。牛谦教授主要研究方向为量子输运、Berry相、自旋霍尔效应、光晶格中的超冷原子、半导体的自旋电子学等,其中一些重要研究成果已入现代版凝聚态物理教科书，标志性综述文章也被知名学校选为研究生教材。牛谦教授于1999年当选美国物理学会会士（APS Fellow）。迄今共发表280余篇论文，其中81篇Phys. Rev. Lett., 3篇Science, 6篇Nature及其子刊，和1篇 Rev. Mod. Phys.，合著Berry相位方面的专著2本，专利一项。研究工作总引用30000余次数，H因子=81。 报告题目：Molecular Berry curvature for lattice dynamics报告摘要：Many phonon properties, such as angular momentum and Hall effect, depend crucially on the absence of time reversal symmetry in lattice dynamics. This could directly originate from an applied magnetic field acting upon the ionic charges, or indirectly through electrons in terms of a molecular Berry curvature acting as a vector potential. We demonstrate in a concrete model how this Berry curvature can arise, how optical modes are split into ones with different chirality, and how acoustic modes can acquire non-reciprocity by additionally breaking spatial inversion symmetry.
杨荣贵 教授
华中科技大学 杨荣贵博士, 华中科技大学能源学院二级教授，美国机械工程师学会会士（ASME Fellow）。杨荣贵博士于2006年获得麻省理工学院机械工程系博士学位。自2006年1月起至2019年，杨荣贵博士历任美国科罗拉多大学博尔德分校机械工程系助理教授、副教授（提前两年获得终身）、终身正教授 （2018年起停薪留职）。杨荣贵博士于2008年入选《科技评论》评选的35位“世界顶尖青年发明家” (TR35 － 35 under 35)，曾获得美国科学基金委杰出青年奖（NSF CAREER Award，2009），美国国防部高级研究计划署青年学者奖（DARPA Young Investigator Award，2008），美国机械工程师学会Bergles-Rohsenow青年学者奖（ASME Bergles-Rohsenow Young Investigator in Heat Transfer，2010），国际热电学会青年学者奖和戈德史密斯奖（Young Investigator Award 2014 和Goldsmid Award 2005）。杨荣贵博士于2017年发明的可规模化生产的无能耗辐射制冷薄膜荣膺《物理世界》评选的2017年“全球十大物理突破”，于2020年度获得国际传热界每两年遴选一位的在热能科学与工程领域做出重大成就的Nukiyama Memorial Award 国际热科学纪念奖，于2021和2022年度被列为科睿唯安高被引科学家。杨荣贵博士迄今为止已发表包括4篇Science、4篇Nature Materials、3篇Science Advances、4篇Joule、1篇Review of Modern Physics在内的200多篇期刊论文。截止至2022年11月，Google Scholar总引用26000余次，H指数80。杨荣贵博士受邀举办过100余场学术讲座，发表了近200多次会议演讲和海报。杨荣贵博士已经培养了30多位博士生和博士后。其中约20位被中国科学院、上海交通大学、同济大学、华中科技大学、东南大学、吉林大学聘为副教授、教授。 报告题目：Ultrafast Laser-Based Transient Thermoreflectance for Thermal Property Measurement报告摘要：准确测量材料的热物性不仅对于传热科学中增进对热量传递机理的理解具有重要意义，而且对于开发应用于能源、电子、光电等领域的新材料也具有重要的实际指导意义。随着材料科学的进步，薄膜材料的研究应用已经到了微纳米级别。由于尺度效应，薄膜材料的热物性与相同材料块体形态下的热物性存在显著差别，主要表现为尺寸依赖性与各向异性，因此对薄膜材料的热输运特性的测量研究极为迫切且关键。因为样品尺寸的限制，传统的测量方法包括稳态法、热线法和闪光法只适用于块体材料的测量，对于微尺度下的热测量存在着明显的时空间分辨率限制，无法满足微尺度下的热测量需求。在过去二十多年中，基于激光的热反射法（TDTR/FDTR）已经发展成一种可靠且功能强大的微尺度热物性测量技术，被广泛用于测量各种薄膜材料及其界面的热性能[1]。本报告从介绍热反射技术的基本原理开始，着重讨论本课题组近年来通过实验方法与数据分析开发热反射法高级应用的一些最新进展，前者包括变频法同时测量材料热导率和比热容[2]、变光斑尺寸法同时测量各向异性材料的面内和纵向热导率[3]、椭圆光斑法测量三维各向异性材料不同方向的热导率[4]，后者包含机器学习模型实现高通量实验数据处理[5]和深度依赖的热物性测量以及声子流体力学模型分析非扩散热输运[6]。讲座最后讨论热反射技术当前存在的局限性及未来发展的一些方向。
Jian-Sheng Wang
Department of Physics, National University of Singapore Jian-Sheng Wang graduated from Jilin University with a B.Sc in 1982. He joined the CUSPEA programme in 1982 and obtained Ph.D. (1987) in Physics from Carnegie-Mellon University. He had postdoctoral positions at Rutgers University (USA), HLRZ Juelich and University of Mainz (Germany). His first job was at Hong Kong Baptist College from 1991 to 1993. Since 1993, he has been at National University of Singapore. He was in the Department of Computational Science, and now is a professor in the Department of Physics. He is a fellow of the American Physical Society (2005) for his outstanding contributions to the development of novel computer simulation algorithms and for their use in the study of phase transitions and critical phenomena. Dr. Jian-Sheng Wang's research field is in Monte Carlo method in statistical physics (with applications in critical phenomena and phase transitions, spin-glasses, nonequilibrium systems known as driven diffusive systems, random sequential adsorption, and research for efficient algorithms). He is well-known for the development of the cluster algorithm by the name Swendsen-Wang algorithm for simulation of Ising and Potts models. His current interests move to quantum thermal transport, nonequilibrium Green's function methods, and near-field radiative heat transfer.
报告题目：Transport of energy, momentum, and angular momentum mediated by photons
报告摘要：Black-body radiation and Casimir force at macroscopic scale are well-known. Black-body radiation is energy transfer at finite temperature, while Casimir force between metal plates is momentum transfer which occur even at temperature of absolute zero. Here, we develop theory at nanoscale. Consider N objects in vacuum each locally may or may not in thermal equilibrium but globally in nonequilibrium steady state. Transport of energy, momentum, or angular momentum is then possible mediated by the electromagnetic fields. It is useful to also consider an extra N+1 “object” which is the “bath-at-infinity” for conservation laws. Very general formulas of Meir-Wingreen type are derived based on the nonequilibrium Green’s functions (NEGF) for the photon field and the Keldysh formalism. The materials properties are represented by photon self-energies. We illustrate the usefulness of the formulas and present some results of calculations, such as the angular momentum emission by a benzene ring driven by electric current, energy and angular momentum emission from a Haldane model of electrons, and also energy, momentum, and angular momentum emissions from graphene edges in nonequilibrium states.
Jian WANG
Shenzhen University and The University of Hong Kong 王健教授1988年获得宾夕法尼亚大学凝聚态理论博士学位，1993年入职香港大学物理系，2010年升任香港大学讲座教授，2020年全职进入深圳大学工作。王健的研究领域为凝聚态理论物理，长期从事纳米电子器件量子输运性能的理论研究，基于非平衡格林函数方法系统发展了纳米器件的非线性直流输运、有限频率交流输运、瞬态响应输运等量子输运理论，相关成果在国际上有重要影响。已在Phys. Rev. Lett、Phys. Rev. B等物理学期刊发表论文300余篇，总引用超过14000次，H因子54（谷歌学术）。1999年获海外华人物理协会亚太成就奖，2013年当选为美国物理学会会士，2017年入选国家重大人才工程计划。王健从事非平衡格林函数研究将近30年，并一直处于该领域的科研前沿。多年来，发展了基于非平衡格林函数的、满足电流守恒和规范不变性的唯象理论和介观理论，同时在散粒噪声、全计数统计、参数泵浦、电化学电容、正常-超导复合结的交流输运以及瞬态量子输运理论等方面有丰富的研究经验。 报告题目：Bulk-Boundary-Transport Correspondence of Higher-Order Topological Insulators报告摘要：Topological phases have corresponding signatures in various spatial domains. For instance, Chern insulator is characterized by Chern number in bulk systems; when it is confined with boundaries, spinless edge states emerges; transport measurements show quantized Hall conductance for open systems. Such a bulk-boundary-transport correspondence is also valid for topological insulators (TI, or quantum spin Hall effect), which is manifested by Z2 invariance, helical edge states, and quantized spin Hall conductance. For higher-order topological insulators (HOTI), the bulk-boundary correspondence has been well established, but quantized transport signature is still absent. We demonstrate that, for a 2D second-order TI induced by applying an in-plane magnetic field in the Z2 invariant first-order TI, integer spin quanta are pumped out per cycle when this magnetic field is rotating, giving rise to the quantization of spin transport. Numerical results show that for finite device systems the onset of quantization of spin current corresponds to the formation of topological corner states labeling 2nd-order TI, suggesting that the quantized spin pump can serve as the quantized transport signature for HOTI that evolved from Z2 invariant first-order TI. The quantized spin current has been tested for different model systems including various versions of BHZ and Kane-Mele models, and it is robust against disorders.