QII-TAQS: Quantum Devices with Majorana Fermions in High-Quality Three-Dimensional Topological Insulator Heterostructures

QII-TAQS：高质量三维拓扑绝缘体异质结构中具有马约拉纳费米子的量子器件

• 批准号: 1936383
• 负责人: Vikram Deshpande
• 金额: $ 163.56万
• 依托单位: University of Utah
• 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: 2019-09-01 至 2023-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1936383&HistoricalAwards=false
• 关键词: QII; TAQS; Quantum; Devices; Majorana

Quantum computers have great potential in important areas such as security and the development of new materials. However, progress toward robust quantum computing has been slow due in part to the issue of coherence of the fundamental logic unit of the quantum computer - the qubit. Topological insulators are the primary state of matter promising protection from loss of coherence but have not yet found application due to materials quality issues. This project works toward "topological quantum computing" by developing novel schemes for realization, detection, and manipulation of the building blocks of a topological quantum computer, viz. Majorana fermions, in heterostructures based on high-quality topological insulators. These studies take advantage of the cross-disciplinary expertise of the investigators (in physics, materials science, and electrical engineering), and integrate with the investigators' education plan, involving the training of undergraduate and graduate students in a collaborative setting to be valuable additions to the quantum workforce. Special courses will be developed by the investigators on quantum materials, phenomena, and computing and their interplay. The excitement of quantum computing will be communicated through novel outreach efforts targeted at the younger generation and underrepresented minority groups, including social media efforts through YouTube and bilingual English-Spanish outreach with local schools and museums. These efforts build on already existing programs of the investigators and aim to broaden participation in education and research.This project aims to establish a materials platform toward the development of practical topological quantum computing. Conventional qubits suffer from decoherence due to the environment and the manipulation of the quantum state itself. It is thought that the advent of topological quantum materials will allow the realization of qubits that are topologically protected from both types of decoherence. An important platform in which to realize topological quantum computing is through Majorana fermions on the surface of 3D topological insulators; however, previous efforts to experimentally realize this goal have been impeded by materials quality issues. The multidisciplinary team will use their recently demonstrated complementary high-quality topological insulator platforms in the form of topological insulator-based van der Waals heterostructures and molecular-beam epitaxially-grown heterostructures to create device configurations of 3D topological insulators together with metals, insulators, ferromagnets, and superconductors. The two approaches are used in tandem toward a variety of Majorana fermions realizations using the same building blocks, based on several different theoretical predictions of both non-chiral and chiral Majorana fermions, modeling of quantum phenomena, and testing of experimental signatures. The various realizations will be compared and an alternative route explored in the form of high-temperature topological superconductors. These experimental studies and device realizations will be done in collaboration with the materials scientists and engineers on the team, taking advantage of the materials modeling and simulation expertise of the computational expert. Such a platform provides an alternative to nanowire Majorana fermions, the prevalent topological quantum computing platform, and promises superior coherence lengths up to millimeters, potentially providing a significant leap toward the development of a 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.

量子计算机在安全和新材料开发等重要领域具有巨大潜力。然而，鲁棒量子计算的进展一直很缓慢，部分原因是量子计算机的基本逻辑单元——量子比特的相干性问题。拓扑绝缘体是物质的主要状态，有希望防止失去相干性，但由于材料质量问题尚未找到应用。该项目致力于“拓扑量子计算”，通过开发基于高质量拓扑绝缘体的异质结构中拓扑量子计算机的构建块（即马约拉纳费米子）的实现，检测和操作的新方案。这些研究利用了研究人员的跨学科专业知识（物理学、材料科学和电气工程），并与研究人员的教育计划相结合，包括在协作环境中培训本科生和研究生，以成为量子劳动力的宝贵补充。研究人员将开发关于量子材料、现象和计算及其相互作用的特别课程。量子计算的兴奋将通过针对年轻一代和未被充分代表的少数群体的新颖外展活动来传播，包括通过YouTube的社交媒体努力，以及与当地学校和博物馆的英西双语外展活动。这些努力建立在已有的研究项目的基础上，旨在扩大对教育和研究的参与。本项目旨在为实用拓扑量子计算的发展建立一个材料平台。由于环境和量子态本身的操纵，传统的量子比特遭受退相干。人们认为，拓扑量子材料的出现将使量子比特在拓扑上免受这两种退相干的影响。三维拓扑绝缘体表面的马约拉纳费米子是实现拓扑量子计算的重要平台；然而，之前通过实验实现这一目标的努力一直受到材料质量问题的阻碍。多学科团队将利用他们最近展示的互补的高质量拓扑绝缘体平台，以基于拓扑绝缘体的范德华异质结构和分子束外延生长异质结构的形式，与金属、绝缘体、铁磁体和超导体一起创建3D拓扑绝缘体的设备配置。基于对非手性和手性马约拉纳费米子的几种不同理论预测、量子现象建模和实验特征测试，这两种方法被用于使用相同的构建块来实现各种马约拉纳费米子。将比较各种实现，并探索高温拓扑超导体形式的替代路线。这些实验研究和设备实现将与团队中的材料科学家和工程师合作完成，利用计算专家的材料建模和模拟专业知识。这种平台为当前流行的拓扑量子计算平台——纳米线马约拉纳费米子提供了一种替代方案，并承诺具有高达毫米的优越相干长度，有可能为拓扑量子计算机的发展提供一个重大飞跃。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

Electrical Manipulation of Topological Phases in a Quantum Anomalous Hall Insulator

• DOI: 10.1002/adma.202207622
• 发表时间: 2023-02-08
• 期刊: ADVANCED MATERIALS
• 影响因子: 29.4
• 作者: Chong, Su Kong;Zhang, Peng;Wang, Kang. L.
• 通讯作者: Wang, Kang. L.

BSTS Synthesis Guided by CALPHAD Approach for Phase Equilibria and Process Optimization

CALPHAD 方法指导下的 BSTS 合成用于相平衡和工艺优化

• DOI: 10.2139/ssrn.3920963
• 发表时间: 2021
• 期刊: SSRN Electronic Journal
• 作者: Alnaser, Husain;Sparks, Taylor D.
• 通讯作者: Sparks, Taylor D.

Landau Levels of Topologically-Protected Surface States Probed by Dual-Gated Quantum Capacitance

• DOI: 10.1021/acsnano.9b09192
• 发表时间: 2020-01-01
• 期刊: ACS NANO
• 影响因子: 17.1
• 作者: Chong, Su Kong;Tsuchikawa, Ryuichi;Deshpande, Vikram V.
• 通讯作者: Deshpande, Vikram V.

A generic dual d-band model for interlayer ferromagnetic coupling in a transition-metal doped MnBi 2 Te 4 family of materials

过渡金属掺杂 MnBi 2 Te 4 系列材料中层间铁磁耦合的通用双 d 带模型

• DOI: 10.1039/d2nr03283j
• 发表时间: 2022
• 期刊: Nanoscale
• 影响因子: 6.7
• 作者: Zhang, Huisheng;Zhang, Jingjing;Zhang, Yaling;Yang, Wenjia;Wang, Yingying;Xu, Xiaohong;Liu, Feng
• 通讯作者: Liu, Feng

Van der Waals heterostructures based on three-dimensional topological insulators

• DOI: 10.1016/j.cossms.2021.100939
• 发表时间: 2021-10
• 期刊: Current Opinion in Solid State & Materials Science
• 影响因子: 11
• 作者: S. Chong;V. Deshpande