Interplay between strongly correlated quantum Hall states and superconductivity

非技术摘要：电子是带电粒子，根据库仑定律，相互靠近的两个电子相互排斥。大量电子的行为可能要复杂得多，有时甚至违反直觉。例如，晶格振动可以将相互排斥的相互作用变成吸引人的作用，从而导致超导，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，在强磁场中，甚至可能会产生更奇怪的状态。在某些场中，电阻消失了，例如在超导体中，但横向(霍尔)电阻仍然不为零，并被量子化。其中一些状态可能是非常特殊类型的超导体，其中电荷是电子电荷的一小部分，这在三维世界中是不可能的。经过多年的研究，人们对这些状态仍然知之甚少，主要是因为可用于研究这些脆弱状态的工具数量非常有限。然而，这些状态中的一些可能拥有创建容错量子计算机所必需的属性。过去，在NSF的支持下，PI的团队开发了一种技术，可以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作为一种新的工具来探测高磁场中的奇异状态，这是一种以前无法通过实验审查的制度。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中。据预测，这样的量子比特具有内在的容错能力。技术摘要：在所有的实验系统中，高迁移率的二维电子气(2DEG)在模型系统中发挥着独特的作用，在这种模型系统中，强烈的电子-电子关联导致在高磁场下形成过多的奇异态，其中一些被预测形成非常规的超导态。Pi的小组最近在制造透明的欧姆超导接触到高迁移率的GaAs中的2DEG方面的突破，打开了这一以前无法进入的超导体-2DEG界面的实验审查范围。初步结果表明，对库珀对注入量子霍尔效应的理解是有限的。研究目标包括详细研究不同拓扑结构的超导电性和强关联分数量子霍尔效应之间的相互作用，这是一种以前无法进入的区域，在那里，令人兴奋的新物理正在等待发现。这项研究可能会导致开发一种新的平台，在那里可以实现高阶非阿贝尔激发，这是拓扑保护容错量子计算的先决条件。教育和外展目标包括在多学科项目中培训学生，并为中学生组织一个物理夏令营。

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.