Theories of Transport and Optical Phenomena in Topological and Correlated Materials

拓扑及相关材料中的输运理论和光学现象

• 批准号: 1918065
• 负责人: Joel Moore
• 金额: $ 44.96万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1918065&HistoricalAwards=false
• 关键词: Theories; Transport; Optical; Phenomena; Topological

NONTECHNICAL SUMMARYThis award supports research and education towards understanding fundamental electronic and optical properties of materials. The electronic and optical properties of materials form the basis of much of modern information technology. Newly discovered materials that go under the classification "topological materials" respond in unique ways to applied electric and magnetic fields, and their properties in some cases can be unusually robust to impurities. The first area of the research portion of this project involves developing theoretical methods to predict and understand properties of topological materials, extending previous work in this area. A particular focus is on improving our understanding of the optical properties that appear when materials are studied with intense laser light. The electrons in these materials appear effectively massless, which creates exciting opportunities for basic science and technology.The other main area of research involves understanding how interactions between electrons in a very clean material lead to fluid-like collective motion of electrons, but with interesting differences compared to the flow of a normal fluid, like water. Understanding these hydrodynamical flows of electrons, or of atoms in an atomic gas, could help in the design of future generations of electronic devices.Educational work in this project includes several activities beyond standard professorial classroom teaching and mentoring of graduate students. The PI is working on a textbook that will be a broad introduction to topological materials, building on his previously published lecture notes. He will pursue outreach activities with local science teachers and with the general public, to give them a sense of recent developments in quantum materials. Undergraduates will be involved in introductory research problems to give them a sense of modern research in the above areas.TECHNICAL SUMMARYThis project combines research in two areas of quantum condensed matter physics with related education and outreach activities. One area of research is concerned with gapless topological states of electrons, building on discoveries of new classes of materials and new phenomena that they enable. The other area involves transport in interacting electron metals including hydrodynamic effects that arise in very clean materials. The main broader impacts of the work to be conducted are on education, primarily of the PI's graduate students but also of scientists and non-scientists more generally, and on understanding the physical underpinnings of future quantum technologies.The PI seeks to understand new kinds of electronic behavior in two areas of quantum condensed matter physics. One area involves topological behavior in metallic or gapless materials. Two recently discovered examples with a long history as theoretical possibilities are the topological bulk semimetals of Weyl or Dirac type. These, and more complicated states such as gapless spin liquids, are subjects of active experimental and theoretical study, but what unique properties they might have is not well understood, compared to the insulating case. This research direction builds on promising recent results on how nonlinear optics and other properties not usually thought of as having a topological origin can become unexpectedly strong and even quantized in topological phases. The supported work will advance the understanding of these kinds of materials more systematically, including interaction effects, and find new examples of topological behavior beyond linear response.Hydrodynamics of simple fluids was arguably the first simplified or "effective" theory of an interacting condensed matter system. The second area of research involves how the modified forms of hydrodynamics arising in the long-time, long-distance dynamics of electrons differ from conventional classical hydrodynamics, which describes a simple fluid like ordinary water. Theoretical work in recent years has given several examples of how electron hydrodynamics in materials can differ from ordinary classical single-component hydrodynamics, whether from extra conserved quantities, the long-ranged nature of Coulomb repulsion, or broken symmetries such as time-reversal or inversion. The behavior of quantum fluids is both experimentally important, for actual transport in practical devices made from very clean materials at small length scales, and is connected to deep questions about thermalization and relaxation rates.Educational activities include undergraduate and graduate student supervision and classroom teaching, lecturing at advanced schools and co-authorship of an introductory textbook on topological matter, and outreach to schools and teachers. One goal of the educational work is to bring some of the magic of recent discoveries in quantum condensed matter physics to a broader audience.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.

该奖项支持研究和教育，以了解材料的基本电子和光学特性。材料的电子和光学特性构成了许多现代信息技术的基础。新发现的材料被归类为“拓扑材料”，它们对外加的电场和磁场有独特的反应，在某些情况下，它们的性质对杂质的抵抗力异常强。本项目研究部分的第一个领域涉及发展理论方法来预测和理解拓扑材料的性质，扩展该领域的先前工作。一个特别的焦点是提高我们对强激光研究材料时出现的光学特性的理解。这些材料中的电子实际上是无质量的，这为基础科学和技术创造了令人兴奋的机会。另一个主要的研究领域涉及理解非常干净的材料中电子之间的相互作用如何导致电子的流体集体运动，但与正常流体（如水）的流动相比有有趣的差异。了解这些电子或原子气体中原子的流体动力学流动，可以帮助设计未来几代电子设备。本项目的教育工作除了标准的教授课堂教学和研究生指导外，还包括几项活动。PI正在编写一本教科书，以他之前发表的课堂笔记为基础，对拓扑材料进行广泛的介绍。他将与当地科学教师和公众开展外展活动，让他们了解量子材料的最新发展。本科生将参与介绍性研究问题，使他们对上述领域的现代研究有一个认识。本项目将量子凝聚态物理的两个领域的研究与相关的教育和推广活动相结合。一个研究领域涉及电子的无间隙拓扑状态，建立在新材料类别和新现象的发现之上。另一个领域涉及相互作用电子金属的输运，包括在非常干净的材料中产生的流体动力学效应。这项工作将对教育产生更广泛的影响，主要是对PI的研究生，但也对科学家和非科学家产生更广泛的影响，以及对未来量子技术的物理基础的理解。PI试图在量子凝聚态物理的两个领域理解新的电子行为。一个领域涉及金属或无间隙材料的拓扑行为。最近发现的两个具有长期理论可能性的例子是Weyl或Dirac型拓扑体半金属。这些和更复杂的状态，如无间隙自旋液体，是积极的实验和理论研究的主题，但与绝缘情况相比，它们可能具有什么独特的性质还没有得到很好的理解。这个研究方向建立在最近有希望的结果上，即非线性光学和其他通常不被认为具有拓扑起源的性质如何在拓扑相中变得出乎意料地强大甚至量化。支持的工作将更系统地推进对这类材料的理解，包括相互作用效应，并找到超越线性响应的拓扑行为的新例子。简单流体的流体动力学可以说是关于相互作用的凝聚态系统的第一个简化或“有效”理论。第二个研究领域涉及到在长时间、远距离的电子动力学中产生的流体力学的修正形式如何与传统的经典流体力学不同，后者描述的是像普通水这样的简单流体。近年来的理论工作给出了几个例子，说明材料中的电子流体力学如何不同于普通的经典单组分流体力学，无论是额外的守恒量，库仑斥力的长期性质，还是时间反转或反转等破缺对称性。量子流体的行为在实验上是重要的，对于由非常干净的材料在小长度尺度上制成的实际设备的实际传输，并且与热化和弛豫速率的深层问题有关。教育活动包括本科生和研究生的监督和课堂教学，在高等学校讲课和合著一本拓扑物质入门教材，以及向学校和教师推广。这项教育工作的一个目标是将量子凝聚态物理学的一些最新发现的魔力带给更广泛的受众。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。

项目成果

Dynamics of fractionalized mean-field theories: Consequences for Kitaev materials

• DOI: 10.1103/physrevb.107.224428
• 发表时间: 2022-06
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Tessa Cookmeyer;J. Moore

Four-Spin Terms and the Origin of the Chiral Spin Liquid in Mott Insulators on the Triangular Lattice

• DOI: 10.1103/physrevlett.127.087201
• 发表时间: 2021-08-19
• 期刊: PHYSICAL REVIEW LETTERS
• 影响因子: 8.6
• 作者: Cookmeyer, Tessa;Motruk, Johannes;Moore, Joel E.
• 通讯作者: Moore, Joel E.

Intrinsic Anomalous Hall Conductivity in a Nonuniform Electric Field

• DOI: 10.1103/physrevlett.126.156602
• 发表时间: 2021-04-12
• 期刊: PHYSICAL REVIEW LETTERS
• 影响因子: 8.6
• 作者: Kozii, Vladyslav;Avdoshkin, Alexander;Moore, Joel E.
• 通讯作者: Moore, Joel E.

Interactions Remove the Quantization of the Chiral Photocurrent at Weyl Points

• DOI: 10.1103/physrevlett.124.196603
• 发表时间: 2020-05-15
• 期刊: PHYSICAL REVIEW LETTERS
• 影响因子: 8.6
• 作者: Avdoshkin, Alexander;Kozii, Vladyslav;Moore, Joel E.
• 通讯作者: Moore, Joel E.

Quasiparticle kinetic theory for Calogero models

Calogero 模型的准粒子动力学理论

• DOI: 10.1088/1751-8121/ac2f8e
• 发表时间: 2021
• 期刊: Journal of Physics A: Mathematical and Theoretical
• 作者: Bulchandani, Vir B;Kulkarni, Manas;Moore, Joel E;Cao, Xiangyu
• 通讯作者: Cao, Xiangyu