CAREER: Realization, Manipulation, and Interaction of Majorana Kramers Pairs

职业：Majorana Kramers 对的实现、操纵和交互

• 批准号: 1945351
• 负责人: Fan Zhang
• 金额: $ 46.73万
• 依托单位: University of Texas at Dallas
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-01 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1945351&HistoricalAwards=false
• 关键词: CAREER; Realization; Manipulation; Interaction; Majorana

NONTECHNICAL SUMMARY This CAREER award supports theoretical research and education in the rapidly developing area of topological states of electronic matter. Over the past decade, the discovery of topological insulators has revolutionized our understanding of the quantum world. The bulk of a topological insulator is insulating, but the surfaces and edges are metallic. A topological insulator is robust; it persists even under deformations of the material. In mathematics, topology is concerned with the properties of an object that are preserved under continuous deformations. Superconductors embody one of the most well studied macroscopic quantum phenomenon. Below a characteristic critical temperature, the electrical resistance of a superconductor drops to zero and magnetic fields are expelled from their interior. Like their topological insulator cousins, topological superconductors exhibit surface states; however, these are predicted to have curious Majorana Fermions, electrons that are correlated in such a way that they behave like a particle that has unusual properties; as a consequence, they may be useful as building blocks for computing and memory in a quantum computer. First proposed as an elementary particle, Majorana Fermions are also fundamentally interesting; a Majorana Fermion is its own antiparticle. The discovery of superconductors that exhibit topological properties has proved difficult. To this end, the PI will leverage well-understood topological and superconducting materials to design new materials systems for realizing topological superconductivity. The PI plans to investigate new phenomena that can arise involving Majorana Fermions and their interplay with crystal symmetry, topology, and interactions in topological superconductors. This research is aimed to stimulate the realization of new phases of electronic matter that can appear in materials. The PI aims to investigate new avenues for realizing topological quantum computing and Majorana Fermion based electronics. The research will stimulate and connect with experiments. The education component involves the implementation of a multi-layered outreach plan that includes: 1) mentoring and training graduate, undergraduate, and high-school students participating in this research, 2) developing an unconventional dual-level course on topological quantum matter, and 3) creating animated online video lessons for global physics education of the general public. In these activities, the PI is committed to promote broadening participation from members of groups underrepresented in science. This CAREER award will contribute to the preparation of future scientists and engineers to discover, invent, and innovate. TECHNICAL SUMMARY This CAREER award supports fundamental research into the realization of symmetry protected topological superconductivity and manipulation of Majorana Kramers pairs in order to develop a deeper understanding of the interplay between symmetry, topology, and interaction. The past decade was an exciting era for condensed matter physics. The discovery of topological insulators has led to an ongoing revolution deepening understanding of quantum matter. The critical temperature of iron-based superconductors has been made unexpectedly high in atomically thin layers. The delicate two-channel Kondo effect as a non-Fermi-liquid paradigm has been achieved in sophisticatedly designed devices. These seemingly unrelated advances in distinct areas can be deeply correlated in a time-reversal-invariant topological superconductor hosting Majorana Kramers pairs. The central goals of this project are: 1) to realize such topological superconductors by designing new material systems involving iron-based superconductors, and 2) to investigate the consequences of Majorana Kramers pairs by studying Josephson effects and many-body interactions mediated by them. The research will be carried out using a diverse set of techniques: phenomenological modeling, topological band theory, first-principles calculations, many-body simulations, and symmetry analysis. The PI aims to establish materials platforms for realizing time-reversal-invariant topological superconductors and manipulating Majorana Kramers pairs. In particular, he aims to identify iron-based topological superconductors with high critical temperatures and advance ideas for the braiding and interaction of Majorana Kramers pairs. Directly applicable to ongoing experiments, these results could advance current knowledge of topological phases of matter and their interplay with symmetry and interaction. Alongside the research, the PI will implement a multi-layered outreach plan that involves: 1) mentoring and training graduate, undergraduate, and high-school students participating in the research, 2) developing an unconventional dual-level course on topological quantum matter, and 3) creating animated online video lessons for global physics education of the general public. In these activities, the PI is committed to promote broadening participation from members of groups underrepresented in science. This CAREER award will contribute to the preparation of future scientists and engineers to discover, invent, and innovate.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.

该职业奖支持电子物质拓扑状态快速发展领域的理论研究和教育。在过去的十年中，拓扑绝缘体的发现彻底改变了我们对量子世界的理解。拓扑绝缘体的主体是绝缘的，但表面和边缘是金属的。拓扑绝缘体是鲁棒的;它甚至在材料变形的情况下仍然存在。在数学中，拓扑学关注的是物体在连续变形下保持不变的性质。超导体是研究得最透彻的宏观量子现象之一。在一个特征临界温度以下，超导体的电阻降为零，磁场从其内部排出。像拓扑绝缘体一样，拓扑超导体也表现出表面态;然而，这些超导体被预测具有好奇的马约拉纳费米子，这些电子以这样一种方式相互关联，它们的行为就像一个具有不寻常性质的粒子;因此，它们可能是量子计算机中计算和存储器的有用构建块。马约拉纳费米子最初是作为一种基本粒子提出的，它也是一种有趣的基本粒子;马约拉纳费米子是它自己的反粒子。发现具有拓扑性质的超导体已被证明是困难的。为此，PI将利用众所周知的拓扑和超导材料来设计实现拓扑超导性的新材料系统。PI计划研究可能出现的新现象，包括马约拉纳费米子及其与晶体对称性，拓扑结构和拓扑超导体中的相互作用的相互作用。这项研究的目的是刺激实现可能出现在材料中的电子物质的新阶段。PI旨在研究实现拓扑量子计算和基于马约拉纳费米子的电子学的新途径。该研究将刺激并与实验联系起来。教育部分涉及实施多层次的推广计划，包括：1）指导和培训参与这项研究的研究生，本科生和高中生，2）开发非传统的拓扑量子物质双层次课程，3）为公众的全球物理教育创建动画在线视频课程。在这些活动中，PI致力于促进科学界代表性不足的群体成员的广泛参与。这个职业奖将有助于未来的科学家和工程师的发现，发明和创新的准备。该职业奖支持实现对称保护拓扑超导性和操纵Majorana Kramers对的基础研究，以更深入地了解对称性，拓扑结构和相互作用之间的相互作用。过去的十年是凝聚态物理学的一个激动人心的时代。拓扑绝缘体的发现引发了一场正在进行的革命，加深了对量子物质的理解。铁基超导体的临界温度在原子级薄层中出乎意料地高。作为一种非费米液体范例，精细的双通道近藤效应已经在精心设计的器件中实现。这些看似不相关的不同领域的进展，可以在一个时间反演不变的拓扑超导体托管马约拉纳Kramers对深刻相关。该项目的中心目标是：1）通过设计涉及铁基超导体的新材料系统来实现这种拓扑超导体，2）通过研究约瑟夫森效应和由它们介导的多体相互作用来研究Majorana Kramers对的后果。这项研究将使用一套不同的技术进行：唯象建模，拓扑能带理论，第一性原理计算，多体模拟和对称性分析。PI的目标是建立材料平台，实现时间反演不变的拓扑超导体和操纵马约拉纳Kramers对。特别是，他的目标是确定具有高临界温度的铁基拓扑超导体，并推进Majorana Kramers对的编织和相互作用的想法。这些结果可直接应用于正在进行的实验，可以推进当前对物质的拓扑相及其与对称性和相互作用的相互作用的认识。除了这项研究，PI还将实施一项多层次的推广计划，包括：1）指导和培训参与研究的研究生，本科生和高中生，2）开发一门关于拓扑量子物质的非传统双层次课程，以及3）为公众的全球物理教育创建动画在线视频课程。在这些活动中，PI致力于促进科学界代表性不足的群体成员的广泛参与。这个职业奖将有助于培养未来的科学家和工程师发现、发明和创新。这个奖项反映了NSF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，被认为是值得支持的。

项目成果

Uncovering Topological Edge States in Twisted Bilayer Graphene

揭示扭曲双层石墨烯中的拓扑边缘态

• DOI: 10.1021/acs.nanolett.2c01481
• 发表时间: 2022
• 期刊: Nano Letters
• 影响因子: 10.8
• 作者: Fortin-Deschênes, Matthieu;Pu, Rui;Zhou, Yan-Feng;Ma, Chao;Cheung, Patrick;Watanabe, Kenji;Taniguchi, Takashi;Zhang, Fan;Du, Xu;Xia, Fengnian
• 通讯作者: Xia, Fengnian

Impact of Electric Field Disorder on Broken-Symmetry States in Ultraclean Bilayer Graphene

电场无序对超净双层石墨烯破缺对称态的影响

• DOI: 10.1021/acs.nanolett.2c02119
• 发表时间: 2022
• 期刊: Nano Letters
• 影响因子: 10.8
• 作者: Geisenhof, Fabian R.;Winterer, Felix;Seiler, Anna M.;Lenz, Jakob;Zhang, Fan;Weitz, R. Thomas
• 通讯作者: Weitz, R. Thomas

Evidence for Dirac flat band superconductivity enabled by quantum geometry

• DOI: 10.1038/s41586-022-05576-2
• 发表时间: 2023-02
• 期刊: Nature
• 影响因子: 64.8
• 作者: Haidong Tian;Xue-Jian Gao;Yuxin Zhang;S. Che;Tianyi Xu;Patrick Cheung;Kenji Watanabe;T. Taniguchi;M. Randeria;Fan Zhang;C. N. Lau;M. Bockrath

Quantum cascade of correlated phases in trigonally warped bilayer graphene

• DOI: 10.1038/s41586-022-04937-1
• 发表时间: 2022-08-11
• 期刊: NATURE
• 影响因子: 64.8
• 作者: Seiler, Anna M.;Geisenhof, Fabian R.;Weitz, R. Thomas
• 通讯作者: Weitz, R. Thomas

Evidence of a room-temperature quantum spin Hall edge state in a higher-order topological insulator

高阶拓扑绝缘体中室温量子自旋霍尔边缘态的证据

• DOI: 10.1038/s41563-022-01304-3
• 发表时间: 2022-07-14
• 期刊: NATURE MATERIALS
• 影响因子: 41.2
• 作者: Shumiya, Nana;Hossain, Md Shafayat;Hasan, M. Zahid
• 通讯作者: Hasan, M. Zahid