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Geometric aspects of optical and transport phenomena in gapless topological phases

无间隙拓扑相中光学和传输现象的几何方面

基本信息

批准号：
1853048
负责人：
Dmytro Pesin
金额：
$ 26.85万
依托单位：
University of Virginia Main Campus
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-08-25 至 2021-11-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1853048&HistoricalAwards=false
关键词：
Geometric aspects optical transport phenomena

项目摘要

NONTECHNICAL SUMMARYThis award supports theoretical research and education on the interplay of geometry and topology with the quantum mechanics, and consequence for the optical and transport properties of materials. Unlike baseballs and other classical objects with motion described by trajectories, electrons in materials are described quantum mechanically by mathematical wave functions. The study of wave functions of systems of many electrons reveals distinct classes leading to a new classification of electronic phases of matter - one that goes beyond the usual classifications based, for example, on the states of aggregation, or on the existence of macroscopic order, like magnetization. These kinds of electronic phases are referred to as topologically, or more broadly, geometrically nontrivial. In this project, the PI aims to bridge the gap between the pure classification of electronic phases and the physical properties of the phases. The PI will focus on developing theory to describe the materials' optical and transport properties, for example, how well the material can conduct electricity or reflect light. The PI will investigate various optical and transport properties in chiral materials.The research is focused on topological phases in chiral materials. A chiral material has a "handedness", so it is distinct from its mirror image. Chirality may arise because of the way the atoms are arranged in the crystal, or induced by external perturbations, like electromagnetic fields, or strain. Regardless of its origin, chirality strongly affects the quantum mechanical behavior of electrons in a material, and so, its experimentally measurable and technologically relevant properties. Examples include magnetization induced by an electron current, and rotation of the plane of transmitted or reflected polarized light. This award also supports educational and training activities, aimed at improving the STEM education in the state of Utah. The primary effort will be directed at the supervision of summer research of high school physics teachers; creation of an extracurricular club for high school students, aimed at introducing its members to collaborative solving of research-type problems in physics; implementation of modern teaching techniques with particular focus on creating an inclusive environment for students from underrepresented groups. Further integration of the research and educational activities will be accomplished through supervision of graduate and undergraduate research, and establishing a journal club for graduate students.TECHNICAL SUMMARYThis award supports theoretical research and education on optical and transport properties of materials with nontrivial band geometry. The objective of this proposal is to provide theoretical insights into electrodynamic, hydrodynamic, and transport properties of disordered gapless topological phases, and to develop new theoretical approaches that would help reveal various geometric aspects of electron behavior in experiment. The research involves three main directions, integrated into an effort aimed at understanding optical and transport phenomena in gapless systems:1. Nonlocal electrodynamics and electron hydrodynamics of gapless topological phases, including the theory of chiral electron hydrodynamics and the chiral vortical effect in crystals. One focus will be on the study of the anomalous Hall effect in the hydrodynamic regime.2. Theory of nonlocal transport in disordered chiral metals. The activity will include a study of the extrinsic contributions to the dynamic chiral magnetic effect; investigation of nonperturbative instanton physics in disordered Dirac systems; development of nonlocal transport theory in nonuniform and strained topological systems.3. Nonlinear optical and magneto-optical phenomena in nonequilibrium states of Weyl and Dirac metals. The study will focus on the topological aspects of nonlinear phenomena in Weyl systems, including topological mechanisms of magneto-photovoltaic effect in Weyl semimetals, and building the theory of current-induced magneto-optical phenomena in metals with nontrivial band geometry.The research will be carried out using a wide spectrum of techniques: quantum kinetic equation for multi-band systems, field-theoretic approaches to itinerant disordered systems, numerical modelling, and ab initio studies. This award also supports educational and training activities, aimed at improving the STEM education in the state of Utah. The primary effort will be directed at the supervision of summer research of high school physics teachers; creation of an extracurricular club for high school students, aimed at introducing its members to collaborative solving of research-type problems in physics; implementation of modern teaching techniques with particular focus on creating an inclusive environment for students from underrepresented groups. Further integration of the research and educational activities will be accomplished through supervision of graduate and undergraduate research, and establishing a journal club for graduate students.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该奖项支持几何和拓扑与量子力学的相互作用的理论研究和教育，以及对材料的光学和输运性质的影响。与棒球和其他用轨迹描述运动的经典物体不同，材料中的电子是用数学波函数来描述量子力学的。对许多电子系统的波函数的研究揭示了不同的类别，导致了物质的电子相的新分类——这种分类超越了通常的分类，例如，基于聚集状态，或基于宏观秩序的存在，如磁化。这些类型的电子相位被称为拓扑，或者更广泛地说，几何上的非平凡。在这个项目中，PI旨在弥合电子相的纯粹分类与相的物理性质之间的差距。PI将专注于发展理论来描述材料的光学和传输特性，例如，材料的导电或反射光性能。PI将研究手性材料的各种光学和输运性质。研究的重点是手性材料的拓扑相。手性材料具有“手性”，因此它与它的镜像不同。手性的产生可能是由于原子在晶体中的排列方式，或由外部扰动（如电磁场或应变）引起的。无论其来源如何，手性强烈影响材料中电子的量子力学行为，因此，它的实验可测量和技术相关性质。例子包括由电子电流引起的磁化，以及透射或反射偏振光平面的旋转。该奖项还支持教育和培训活动，旨在改善犹他州的STEM教育。研究的重点是对高中物理教师暑期科研工作的指导；创建高中学生课外俱乐部，旨在引导其成员合作解决物理研究型问题；实施现代教学技术，特别注重为来自代表性不足群体的学生创造一个包容的环境。进一步整合研究和教育活动将通过研究生和本科生的研究监督，并建立一个研究生杂志俱乐部。该奖项支持具有非平凡带几何的材料的光学和输运性质的理论研究和教育。本提案的目的是提供对无序无间隙拓扑相的电动力学、流体动力学和输运性质的理论见解，并开发新的理论方法，有助于揭示实验中电子行为的各种几何方面。该研究涉及三个主要方向，旨在理解无间隙系统中的光学和输运现象。无间隙拓扑相的非局部电动力学和电子流体力学，包括手性电子流体力学理论和晶体中的手性涡效应。一个重点将是研究流体力学中的反常霍尔效应。无序手性金属的非定域输运理论。该活动将包括对动态手性磁效应的外在贡献的研究；无序Dirac系统中非微扰瞬子物理的研究非均匀和应变拓扑系统中非局部输运理论的发展。Weyl和Dirac金属非平衡态的非线性光学和磁光现象。研究将集中在Weyl系统中非线性现象的拓扑方面，包括Weyl半金属中磁光电效应的拓扑机制，以及建立具有非平凡带几何的金属中电流诱导磁光现象的理论。该研究将使用广泛的技术：多波段系统的量子动力学方程，流动无序系统的场论方法，数值模拟和从头开始研究。该奖项还支持教育和培训活动，旨在改善犹他州的STEM教育。研究的重点是对高中物理教师暑期科研工作的指导；创建高中学生课外俱乐部，旨在引导其成员合作解决物理研究型问题；实施现代教学技术，特别注重为来自代表性不足群体的学生创造一个包容的环境。进一步整合研究和教育活动将通过研究生和本科生的研究监督，并建立一个研究生杂志俱乐部。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。