Creating, manipulating, and detecting Majorana fermion states in hybrid superconductor-topological insulator Josephson devices

在混合超导拓扑绝缘体约瑟夫森器件中创建、操纵和检测马约拉纳费米子态

• 批准号: 1610114
• 负责人: Dale Van Harlingen
• 金额: $ 48.9万
• 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: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1610114&HistoricalAwards=false
• 关键词: Creating; manipulating; detecting; Majorana; fermion

Non-Technical Abstract: This award supports experimental research aimed at understanding a newly-discovered class of materials and enabling future advanced electronic devices. The research focuses on topological materials, called "topological" because their properties depends primarily on the topology, or geometry, of their electronic structure. By fabricating and measuring a series of advanced devices that integrate these topological materials with superconductors, the capabilities and limitations of this rapidly emerging field will be explored. In addition to their possible technological applications, these unique materials can be implemented in electronic circuits to create a new type of computer platform in which the information is stored in states protected from the detrimental effects of the environment. This is a unique feature of topological devices that has the potential to extend dramatically the speed and capability of large-scale computers. In addition to 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 four interwoven categories: (1) mapping the location of Majorana fermions via spectroscopy and imaging, looking for the zero-energy states in the gap that are signatures of these unique states, (2) probing the dynamics of Majorana fermions by phase-sensitive Josephson interferometry, searching for the periodic current-phase relation that is a characteristic signature of the Majorana fermions states, (3) manipulating and detecting the parity of Majorana fermions, exploring ways to measuring the parity via direct measurements of specific components of the supercurrent using Josephson electronics, and (4) verifying and using the non-Abelian statistics of Majorana fermions, the most characteristic and intriguing aspect of Majorana fermion modes and the property that makes them highly attractive for quantum information processing and computing. 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.

非技术摘要：该奖项支持旨在理解一类新发现的材料并使未来的先进电子设备成为可能的实验研究。这项研究的重点是拓扑材料，称为“拓扑”，因为它们的性质主要取决于它们的电子结构的拓扑或几何。通过制造和测量一系列将这些拓扑材料与超导体相结合的先进器件，将探索这一迅速崛起的领域的能力和局限性。除了它们可能的技术应用外，这些独特的材料还可以在电子电路中实现，以创建一种新型的计算机平台，其中的信息存储在不受环境有害影响的状态下。这是拓扑设备的一个独特功能，它有可能极大地扩展大型计算机的速度和能力。除了这个项目可能产生的新的科学和应用之外，这个研究项目还让不同的博士后研究人员、研究生和本科生接触到与新材料和现象的开发和应用相关的科学问题和实验技术。在材料科学和器件物理的界面上的这种培训已经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：在混合超导体-拓扑绝缘体系统中，已经预测到令人兴奋的新现象，其中对关联产生有效的复杂的超导序参数，表现为手征边缘态，拓扑保护的表面态，以及作为它们自己的反粒子的奇异激发的Majorana费米子。这个项目的重点是核化这些奇异的激发，并以可控的方式操纵它们，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它们独特的非阿贝尔统计，并开发功能方法来成像、操作、读出编码其关键相位信息的宇称，并编织它们执行逻辑运算，所有这些关键步骤都是理解这些新状态的基本物理并为量子信息处理、量子计量学和量子模拟/计算创造技术的关键步骤。关键实验分为四个相互交织的类别：(1)通过光谱学和成像绘制Majorana费米子的位置图，寻找这些独特状态的特征带隙中的零能态，(2)通过相敏约瑟夫森干涉测量Majorana费米子的动力学，寻找作为Majorana费米子态特征的周期性电流-相位关系，(3)操纵和检测Majorana费米子的宇称，探索通过直接测量超导电流的特定分量来测量宇称的方法，以及(4)验证和使用Majorana费米子的非阿贝尔统计，Majorana费米子模式最具特点和最吸引人的方面，以及使其在量子信息处理和计算中具有极大吸引力的性质。拓扑物理领域是一个非常新的领域，世界各地的研究人员刚刚开始集体探索材料、测量和理论概念，这些概念对于理解Majorana费米子以及如何在电子电路中利用它们将是重要的。该项目探索了这一领域中尚未解决的关键问题，以及在理解奇异的Majorana费米子的性质和在功能超导电路中实施它们方面取得重大进展的途径。它还为学生提供培训该领域的科学和技术的机会，预计该领域将在未来几年内增长。