Interplay between strongly correlated quantum Hall states and superconductivity

强相关量子霍尔态与超导之间的相互作用

• 批准号: 1610139
• 负责人: Leonid Rokhinson
• 金额: $ 30万
• 依托单位: Purdue University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-15 至 2019-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1610139&HistoricalAwards=false
• 关键词: Interplay; between; strongly; correlated; quantum

Non-technical Abstract:Electrons are charged particles, and two electrons brought close to each other repel according to the Coulomb's law. Behavior of a large number of electrons may be much more complex and sometimes counterintuitive. For example, lattice vibrations can change repulsive interactions into attractive resulting in superconductivity, a state with no resistance to electrical current. In two dimensional systems, where electrons are confined to a thin sheet of material, even more exotic states can develop in high magnetic fields. At some fields resistance vanishes, as in superconductors, but transverse (Hall) resistance remains non-zero and is quantized. Some of these states may be superconductors of a very special type, where charges are fractions of an electron charge, something impossible in a three dimensional world. After many years of studies these states are still poorly understood, primarily due to a very limited amount of tools that can be used to investigate these fragile states. Yet some of these states may possess properties necessarily to create fault tolerant quantum computers. In the past with NSF support, the PI's group developed a technology to form high quality electrical contacts between conventional superconductors and two dimensional electron systems. Our research team is now using superconductivity as a new tool to probe exotic states at high magnetic fields, a regime previously not accessible to experimental scrutiny. This research can potentially lead to the development of quantum bits where quantum information is encoded in the topology of the system. Such quantum bits are predicted to be inherently fault-tolerant. Educational and outreach goals include training students in a multidisciplinary program and organization of a Summer Physics Camp for middle school students.Technical Abstract:Among all the experimental systems high mobility two-dimensional electron gases (2DEG) play a unique role of a model system where strong electron-electron correlations lead to the formation of a plethora of exotic states at high magnetic fields, some of them predicted to form unconventional superconducting states. The PI's group's recent breakthrough in the fabrication of transparent ohmic superconducting contacts to high mobility 2DEG in GaAs opens this previously inaccessible regime of superconductor-2DEG interface to experimental scrutiny. Preliminary results indicate the limited understanding of Cooper pair injection into a quantum Hall effect regime. The research objectives include detailed investigation of interplay between topologically distinct superconductivity and strongly correlated fractional quantum Hall effect, a previously inaccessible regime where exciting new physics is waiting to be discovered. This research can potentially lead to the development of a new platform where high order non-Abelian excitations can be realized, a prerequisite for topologically protected fault-tolerant quantum computing. Educational and outreach goals include training students in a multidisciplinary program and organization of a Summer Physics Camp for middle school students.

非技术摘要：电子是带电粒子，根据库仑定律，两个电子相互靠近会相互排斥。大量电子的行为可能要复杂得多，有时甚至违反直觉。例如，晶格振动可以将排斥相互作用变为吸引相互作用，从而导致超导性，一种对电流没有阻力的状态。在二维系统中，电子被限制在一张薄薄的材料上，在高磁场中甚至可以发展出更奇特的状态。在某些领域电阻消失，如在超导体，但横向（霍尔）电阻保持非零，并量化。这些状态中的一些可能是非常特殊类型的超导体，其中电荷是电子电荷的分数，这在三维世界中是不可能的。经过多年的研究，这些状态仍然知之甚少，主要是由于可用于研究这些脆弱状态的工具非常有限。然而，其中一些状态可能具有创建容错量子计算机所必需的属性。在过去的NSF支持下，PI的团队开发了一种技术，在传统超导体和二维电子系统之间形成高质量的电接触。我们的研究团队现在正在使用超导性作为一种新的工具来探测高磁场下的奇异状态，这是一种以前无法通过实验检查的机制。这项研究可能会导致量子比特的发展，其中量子信息被编码在系统的拓扑结构中。这样的量子比特被预测为固有的容错。教育和推广的目标包括培训学生在一个多学科的计划和组织的暑期物理夏令营的中学生。技术摘要：在所有的实验系统中，高迁移率的二维电子气体（2DEG）发挥了独特的作用，一个模型系统，强电子-电子相关导致形成过多的异国情调的国家在高磁场，其中一些预测形成非常规的超导状态。PI的小组最近在GaAs中制造高迁移率2DEG的透明欧姆超导接触方面取得了突破，为实验检查打开了这种以前无法进入的超导体-2DEG界面制度。初步结果表明，有限的理解库珀对注入到量子霍尔效应制度。研究目标包括详细研究拓扑上不同的超导性和强相关的分数量子霍尔效应之间的相互作用，这是一个以前无法进入的领域，令人兴奋的新物理正在等待被发现。 这项研究可能会导致一个新的平台的发展，高阶非阿贝尔激发可以实现，拓扑保护容错量子计算的先决条件。教育和推广目标包括在多学科方案中培训学生，并为中学生组织暑期物理夏令营。