CAREER: Probing and Braiding Chiral Majorana Fermions in Quantum Anomalous Hall Insulator-Superconductor Hybrid Structures

职业：探测和编织量子反常霍尔绝缘体-超导混合结构中的手性马约拉纳费米子

• 批准号: 1847811
• 负责人: Cui-Zu Chang
• 金额: $ 65.89万
• 依托单位: Pennsylvania State Univ University Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-05-01 至 2025-04-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1847811&HistoricalAwards=false
• 关键词: CAREER; Probing; Braiding; Chiral; Majorana

Non-technical abstract:The rapidly increasing need for high computing power requires a drastic paradigm shift away from traditional computers based on silicon transistors. A quantum computer, which makes use of quantum physics to store information and execute calculations is expected to be vastly more efficient and hence more powerful than a traditional computer. An attractive scheme towards quantum computation involves a newly-discovered class of materials, called topological insulators, where the interior is insulating but the surface is electrically conducting. Magnetic elements can be incorporated into such a topological insulator sample to achieve a curious phenomenon called quantum anomalous Hall effect. In this state the surface electrons are confined to the edges of the sample and flow without resistance. It has been predicted that quantum computation can be achieved in a device where this resistance-free edge current of the quantum anomalous Hall insulator is utilized. This project aims to test this prediction. Active education and outreach programs for graduate and undergraduate students, K-12 students and teachers, and the general public are integral part of planned work.Technical Abstract:The coupling of the spin-polarized dissipation-free edge state of a quantum anomalous Hall insulator and a conventional superconductor has been predicted to harbor a topological superconductivity phase that supports gapless Majorana fermion excitation at surfaces or edges of the sample. Topological superconductivity can reveal transformative new physics, such as non-Abelian statistics, and enable new architectures for topological quantum computation. In this project, the principal investigator pursues the quantum coherent oscillations as a function of vortices number in a micrometer-sized quantum anomalous Hall/superconductor Mach-Zehnder interferometer to ascertain the existence of the Majorana fermion and the non-Abelian braiding of such Majorana fermions in a quantum anomalous Hall/superconductor device with Corbino geometry. This project also explores the transport signatures of external electrical field induced topological superconductivity phase in quantum anomalous Hall/superconductor hybrid structures under homogenous magnetization and multiple chiral Majorana fermions in high-Chern-number quantum anomalous Hall/superconductor heterostructures. The success of the project will lead to significant new understanding of the microscopic mechanisms of topological superconductivity phase and carries far-reaching technological implications especially for the development of the topological quantum computer.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.

非技术摘要：对高计算能力快速增长的需求要求从基于硅晶体管的传统计算机进行剧烈的范式转变。量子计算机利用量子物理来存储信息和执行计算，预计将比传统计算机效率高得多，因此功能更强大。量子计算的一个吸引人的方案涉及一种新发现的材料，称为拓扑绝缘体，其内部是绝缘的，但表面是导电的。磁性元素可以加入到这样的拓扑绝缘体样品中，以实现一种奇怪的现象，称为量子反常霍尔效应。在这种状态下，表面电子被限制在样品的边缘并无阻力地流动。据预测，量子计算可以在利用量子反常霍尔绝缘体的无电阻边缘电流的器件中实现。本项目旨在验证这一预测。对研究生和本科生、K-12学生和教师以及公众的积极教育和推广计划是计划工作的组成部分。技术摘要：量子反常霍尔绝缘体的自旋极化无耗散边缘态与传统超导体的耦合已经被预测为在样品表面或边缘支持无间隙马约拉纳费米子激发的拓扑超导相。拓扑超导可以揭示变革性的新物理学，如非阿贝尔统计，并为拓扑量子计算提供新的架构。在这个项目中，首席研究员在一个微米大小的量子反常霍尔/超导体马赫-曾德干涉仪中进行了作为旋涡数函数的量子相干振荡，以确定马约拉纳费米子的存在以及这种马约拉纳费米子在具有Corbino几何的量子反常霍尔/超导体装置中的非阿贝尔编织。本项目还探讨了均匀磁化下量子反常霍尔/超导杂化结构中外电场诱导拓扑超导相的输运特征，以及高chern数量子反常霍尔/超导异质结构中的多手性Majorana费米子。该项目的成功将导致对拓扑超导相微观机制的重要新认识，特别是对拓扑量子计算机的发展具有深远的技术意义。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

Tuning the Chern number in quantum anomalous Hall insulators

• DOI: 10.1038/s41586-020-3020-3
• 发表时间: 2020-12
• 期刊: Nature
• 影响因子: 64.8
• 作者: Yi-Fan Zhao;Ruoxi Zhang;Ruobing Mei;Ling Zhou;H. Yi;Ya-Qi Zhang;Jiabin Yu;Run Xiao;Ke Wan

Electrical switching of the edge current chirality in quantum anomalous Hall insulators

• DOI: 10.1038/s41563-023-01694-y
• 发表时间: 2022-05
• 期刊: Nature Materials
• 影响因子: 41.2
• 作者: Wei Yuan;Lingjie Zhou;Kai-Jheng Yang;Yi-Fan Zhao;Ruoxi Zhang;Zijie Yan;Deyi Zhuo;Ruobing Mei;Yang Wang;H. Yi;M. Chan;M. Kayyalha;Chaoxing Liu;Cui-Zu Chang

Crossover from Ising- to Rashba-type superconductivity in epitaxial Bi2Se3/monolayer NbSe2 heterostructures

• DOI: 10.1038/s41563-022-01386-z
• 发表时间: 2021-12
• 期刊: Nature Materials
• 影响因子: 41.2
• 作者: H. Yi;Lunhui Hu;Yuanxi Wang;Run Xiao;Jiaqi Cai;D. R. Hickey;C. Dong;Yi-Fan Zhao;Lingjie Zhou;Ruoxi Zhang;A. Richardella;N. Alem;J. Robinson;M. Chan;Xiaodong Xu;N. Samarth;Chaoxing Liu;Cui-Zu Chang

Interface-induced superconductivity in magnetic topological insulators

• DOI: 10.1126/science.adk1270
• 发表时间: 2024-02
• 期刊: Science
• 影响因子: 56.9
• 作者: H. Yi;Yi-Fan Zhao;Ying-Ting Chan;Jiaqi Cai;Ruobing Mei;Xianxin Wu;Zijun Yan;Lingjie Zhou;Ruoxi Zhang;Zihao Wang;Stephen Paolini;Run Xiao;Ke Wang;A. Richardella;John Singleton;Laurel E. Winter;T. Prokscha;Zaher Salman;Andreas Suter;P. Balakrishnan;A. Grutter;Moses H. W. Chan;N. Samarth;Xiaodong Xu;Weida Wu;Chaozhi Liu;Cui-Zu Chang

Atomically thin half-van der Waals metals enabled by confinement heteroepitaxy

• DOI: 10.1038/s41563-020-0631-x
• 发表时间: 2020-03-10
• 期刊: NATURE MATERIALS
• 影响因子: 41.2
• 作者: Briggs, Natalie;Bersch, Brian;Robinson, Joshua A.
• 通讯作者: Robinson, Joshua A.