Topology, interactions, and disorder in exotic quantum materials

奇异量子材料中的拓扑、相互作用和无序

• 批准号: RGPIN-2020-06999
• 负责人: Maciejko, Joseph
• 金额: $ 4.44万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=718538
• 关键词: Topology; interactions; disorder; exotic; quantum

Ordinary phases of mattersolid, liquid, and gasare distinguished by emergent macroscopic properties, such as rigidity or the lack thereof, which are a consequence of how atoms microscopically arrange themselves, but also transcend the minute details of such arrangements. At temperatures near absolute zero, quantum effects allow for qualitatively new patterns of microscopic arrangements that produce novel emergent properties beyond those of ordinary matter, such as superfluidity, magnetism, and superconductivity. The field of quantum materials, a key subdiscipline of condensed matter physics, attempts to theoretically understand such quantum phases of matter and the transitions between them, and to experimentally discover materials that realize them. In the past ten years or so, this field has witnessed a veritable revolution. Recognized in part by the 2016 Nobel Prize in Physics, the prediction of topological insulatorswhere an insulating bulk coexists with a robust metallic surfacehas received wide experimental confirmation and evolved into a thriving branch of mainstream condensed matter physics. The discovery of exotic magnetic materials where quantum “fuzziness” is so strong as to completely demagnetize them may signal the long-awaited discovery of the spin liquid, an exotic quantum state of matter first theorized in the 1970s. The unusual behavior of ultrathin materials in strong magnetic fields reveals new cooperative behaviors previously thought impossible, such as the emergence of collective excitations with only a fraction of the charge of an electron. Many of the unusual properties of those exotic quantum materials, such as metallic surface states and fractionalized excitations, may lead to novel technological applications in low-power electronics and quantum computing. A necessary first step towards such applications, the development of a complete theoretical understanding of this bewildering variety of new phenomena is however hindered by the lack of a unified conceptual framework and complicated by the unavoidable presence of imperfections and impurities in real materials. Supported in part by this NSERC Discovery Grant, my research program aims to achieve a deeper and more unified understanding of three broad classes of quantum materialstopological materials, spin liquids, and ultrathin materials in high magnetic fieldsthrough the construction of mathematical models that incorporate both quantum effects and material imperfections, and the analysis of those models via cutting-edge theoretical methods. By training undergraduate research assistants (URAs), graduate students, and postdoctoral fellows (PDFs) in a wide range of broadly applicable analytical and computational skills, this research will help maintain Canada's leadership in the field of quantum materials and will contribute to grow our country's knowledge-based economy.

物质，液体和气体的普通阶段通过出现的宏观特性（例如刚度或缺乏）区分，这是原子如何在显微镜上安排自己的结果，但也超越了此类布置的细节细节。在接近绝对零的温度下，量子效应允许微观布置的定性新模式产生超出普通物质的新兴特性，例如超流体，磁性和超导性。量子材料的领域是凝结物理物理学的关键子学科，试图从理论上理解物质的量子阶段及其之间的过渡，并试图在实验中发现实现它们的材料。 在过去的十年左右的时间里，该领域见证了一场名副其实的革命。拓扑绝缘因子的预测部分被2016年诺贝尔物理学奖所认可，在该预测中，具有强大的金属表面的绝缘散装共存获得了广泛的实验确认，并演变成主流凝结物理物理学的繁荣分支。量子“模糊性”的异国情调材料的发现非常强，以至于完全消除它们可能会表明期待已久的旋转液体的发现，这是一种旋转液体，这是一种奇异的物质状态，首先是1970年代理论上的。超薄材料在强磁场中的异常行为揭示了以前认为不可能的新合作行为，例如，仅具有电子电荷的一小部分集体兴奋的出现。这些异国情调的量子材料（例如金属表面状态和分数激发）的许多异常特性可能导致低功率电子和量子计算中的新技术应用。迈出了这种应用的必要第一步，是由于缺乏统一的概念框架而阻碍了对这种令人困惑的新现象的完整理论理解的发展，并且由于真实材料中的不完美和杂质的不可避免的存在而变得复杂。 我的研究计划在一定程度上支持了这项NSERC Discovery Grant，旨在通过在高磁性领域中对三种广泛的量子材料材料，旋转液体和超薄材料进行更深入，更统一的了解，通过结合量子效应和材料不完美的数学模型，以及通过高级范围的模型通过高级设计模型分析这些模型。通过培训本科研究助理（URA），研究生和博士后研究员（PDFS），以广泛适用的分析和计算技能培训，这项研究将有助于维持加拿大在量子材料领域的领导地位，并为增长我们国家的基于知识的经济增长。