Manipulating Majorana bound states in S-TI-S Josephson junction networks: braiding, fusion, and parity dynamics

操纵 S-TI-S 约瑟夫森结网络中的马约拉纳束缚态：编织、融合和宇称动力学

• 批准号: 2004825
• 负责人: Dale Van Harlingen
• 金额: $ 76万
• 依托单位: University of Illinois at Urbana-Champaign
• 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: 2020-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2004825&HistoricalAwards=false
• 关键词: Manipulating; Majorana; bound; states; TI

Non-Technical Abstract:This award combines experimental condensed matter physics and quantum information science research aimed at understanding a newly-discovered class of materials and developing schemes for incorporating them into advanced electronic devices for quantum computing. The focus is on topological materials whose properties depend on the topology, or geometry, of their electronic structure, enabling novel electronic states that can carry and control currents in unique ways. Fabricating and measuring a series of advanced hybrid devices that integrate these topological materials with superconductors will enable exploration of the capabilities and limitations of this approach that has been predicted to exhibit new physical phenomena and electronic properties. In addition to their scientific interest, these unique materials can be implemented in electronic circuits to create a new type of computer platform in which the information is stored in quantum states protected from the detrimental effects of the environment, a unique feature of topological devices that has the potential to extend dramatically the speed and capability of large-scale computers. Through the new science and applications that may arise from this project, this research program exposes a diverse cadre of postdoctoral researchers, graduate research students, and undergraduate students to scientific issues and experimental techniques relevant to the development and applications of new materials and phenomena. This training at the interface of materials science and device physics has been demonstrated to be highly effective in launching the careers of scientists and engineers in high technology fields.Technical Abstract: Exciting new phenomena have been predicted to arise in hybrid superconductor-topological insulator systems in which pair correlations induce an effective complex superconducting order parameter exhibiting chiral edge states, topologically-protected surface states, and Majorana fermions, exotic excitations that are their own antiparticles. This project focuses on schemes to nucleate these exotic excitations and manipulate them in controllable ways to verify their existence and explore their stability and dynamics. A series of specific experiments are designed to reveal their unique non-Abelian statistics and to develop functional approaches to image, manipulate, readout the parity that encodes their critical phase information, and braid them to perform logical operations, all critical steps toward understanding the underlying physics of these novel states and crafting a technology for quantum information processing, quantum metrology, and quantum simulation/computing. Key experiments fall into two categories: (1) investigation and characterization of the parity dynamics of Majorana states in S-TI-S Josephson junctions and determine the materials and device properties that affect it --- this includes experiments to observe and characterize parity fluctuations, modeling of the interplay of Josephson phase dynamics and parity transitions, and ways to improve parity lifetimes, (2) development of schemes for braiding, fusion, and parity readout of Majorana modes in the S-TI-S platform, all important capabilities required to implement scheme. The field of topological physics is very new and researchers worldwide are collectively just starting to explore the materials, measurements, and theoretical concepts that will be important in achieving an understanding of Majorana fermions and how to exploit them in electronic circuits. This project explores the key unsolved problems in this field and paths for making significant advances in understanding the nature of exotic Majorana fermions and implementing them in functional superconductor circuits. It also provides opportunities to train students in the science and technology of this field that is anticipated to grow in the coming years.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.

摘要：该奖项将实验凝聚态物理和量子信息科学研究相结合，旨在理解一类新发现的材料，并制定将其纳入量子计算先进电子设备的方案。重点是拓扑材料，其性质取决于其电子结构的拓扑或几何形状，从而实现能够以独特方式携带和控制电流的新型电子状态。制造和测量一系列先进的混合设备，将这些拓扑材料与超导体相结合，将使探索这种方法的能力和局限性成为可能，这种方法已经被预测为展示新的物理现象和电子特性。除了它们的科学意义之外，这些独特的材料可以在电子电路中实现，以创建一种新型的计算机平台，在这种平台中，信息存储在量子态中，免受环境的有害影响，这是拓扑设备的一个独特特征，它有可能极大地扩展大型计算机的速度和能力。通过该项目可能产生的新科学和应用，该研究计划使博士后研究人员、研究生和本科生接触到与新材料和新现象的开发和应用相关的科学问题和实验技术。这种材料科学和器件物理结合的培训已被证明在高科技领域的科学家和工程师的职业生涯中是非常有效的。技术摘要：在超导体-拓扑绝缘体的杂化系统中，预计会出现令人兴奋的新现象，在这种系统中，对相关诱导出一个有效的复杂超导序参量，表现出手性边缘态、拓扑保护表面态和马约拉纳费米子（它们本身就是反粒子的奇异激发）。本项目重点研究如何使这些奇异的激励成核，并以可控的方式对其进行操纵，以验证它们的存在，并探索它们的稳定性和动力学。一系列特定的实验旨在揭示其独特的非阿贝尔统计，并开发功能方法来成像，操纵，读取编码其关键相位信息的宇称，并将其编织以执行逻辑运算，所有关键步骤都是为了理解这些新状态的潜在物理，并为量子信息处理，量子计量和量子模拟/计算技术制作技术。关键实验分为两类：(1)调查和表征S-TI-S Josephson结中Majorana态的宇称动力学，并确定影响它的材料和器件特性——这包括观察和表征宇称波动的实验，Josephson相动力学和宇称转换相互作用的建模，以及改善宇称寿命的方法；(2)开发S-TI-S平台中Majorana模式的编织、融合和宇称读取方案；实现方案所需的所有重要功能。拓扑物理学是一个非常新的领域，全世界的研究人员都刚刚开始探索材料、测量和理论概念，这些对于理解马约拉纳费米子以及如何在电子电路中利用它们非常重要。本项目探索了该领域尚未解决的关键问题，以及在理解外来马约拉纳费米子的性质并将其应用于功能超导体电路方面取得重大进展的途径。它还提供了在该领域的科学和技术方面培训学生的机会，预计在未来几年将有所增长。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

Decoherent quench dynamics across quantum phase transitions

• DOI: 10.21468/scipostphys.11.4.084
• 发表时间: 2021-03
• 期刊: SciPost Physics
• 影响因子: 5.5
• 作者: W. Kuo;D. Arovas;S. Vishveshwara;Yi-Zhuang You

Signatures of Majorana bound states and parity effects in two-dimensional chiral p -wave Josephson junctions

• DOI: 10.1103/physrevb.105.214521
• 发表时间: 2022-02
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Nick Abboud;V. Subramanyan;Xiao-Qi Sun;G. Yue;D. V. Van Harlingen;S. Vishveshwara