CAREER: Are Majorana Bound States Non-Abelian Particles?

*技术摘要*本项目将使用低维系统中的Majorana粒子演示非阿贝尔量子统计。与玻色子和费米子不同的是，当两个马约拉纳交换位置时，它们的最终量子态与起始态不同。纳米器件的实验将结合低温介观输运测量、微波量子位操纵技术和新材料的开发。该提案的目标将通过将马约拉纳量子比特的三个积木组合在一起来实现。具体地说，该项目将研究(1)如何抑制由于超导体中的非平衡准粒子导致的马约拉纳退相干；(2)能否测量两个马约拉纳的量子态；(3)如何在太空中进行马约拉纳的交换，或者说“编织”。该方案的成功将为未来的拓扑量子计算奠定基础。非阿贝尔统计的演示将对基础教科书层面的科学教育产生影响，并使整个社会更深刻地认识到支配量子世界的基本规律。该项目将培养一名研究生，培养基础和实用技能，如纳米制造和低温实验室技术。将开发一门针对研究生和大四本科生的量子输运新课程，特别强调拓扑效应。在微观尺度上构成我们世界的非技术摘要*粒子被分为两类：费米子和玻色子。它们遵守量子力学的奇怪规则。例如，作为费米子的两个电子不能同时出现在同一位置，而对于作为玻色子的光子来说，这是完全允许的。这个项目将尝试演示一种新的第三类粒子，称为非阿贝尔任意子。所有的电子都是不可区分的，这意味着如果其中两个电子改变位置，我们的世界看起来完全相同。但是，如果两个非阿贝尔粒子互换，宇宙就会转变成由拓扑学定律规定的不同状态。这里将研究的特定类型的任意子是Majorana准粒子，这种粒子是它们自己的反粒子，可以在类似晶体管的纳米级设备中产生。这一提议的成功将为未来依赖于非阿贝尔粒子互换或“编织”的拓扑量子计算奠定基础。非阿贝尔粒子的演示将对基础教科书层面的科学教育产生影响，并使整个社会对支配量子世界的基本定律有更深的认识。该项目将培养一名研究生，培养基础和实用技能，如纳米制造和低温实验室技术。将开发一门针对研究生和大四本科生的关于量子输运的新课程，特别强调拓扑效应。为协助广泛传播和分享科学知识，将建立网站，以便快速讨论新的成果，以及获取原始数据和进行讨论。

****Technical Abstract****This project will demonstrate non-abelian quantum statistics using Majorana particles in low-dimensional systems. In contrast with bosons and fermions, when two Majoranas exchange positions their final quantum state is not identical to the starting state. Experiments on nanoscale devices will combine low-temperature mesoscopic transport measurements, microwave quantum bit manipulation techniques and the development of new materials. The goal of the proposal will be reached by putting together three building blocks of a Majorana quantum bit. Specifically, the project will investigate (1) ways to suppress decoherence of Majoranas due to non-equilibrium quasiparticles in superconductors; (2) whether the quantum state of two Majoranas can be measured; (3) how to perform the exchange, or "braiding", of Majoranas in space. The success of this proposal will lay the foundation for future topological quantum computation. The demonstration of non-abelian statistics will have an impact on science education at the basic textbook level and bring deeper awareness by the society at large of the fundamental laws governing the quantum world. The project will train a graduate student, which develop fundamental and practical skills such as nanofabrication and laboratory techniques at low temperatures. A new course on Quantum Transport aimed at graduate students and senior undergraduates will be developed with a special emphasis on topological effects.****Non-Technical Abstract****Particles that comprise our world at the microscopic scale are divided in two classes: fermions and bosons. They obey strange rules of quantum mechanics. For example, two electrons, which are fermions, cannot be at the same place at the same time, while for photons, which are bosons, this is perfectly allowed. This project will attempt to demonstrate a new, third class of particles called the non-abelian anyons. All electrons are indistinguishable, which means that our world looks exactly the same if two of them change their places. But if two non-abelian particles are interchanged the Universe transitions into a different state dictated by the laws of topology. The particular class of anyons that will be studied here are Majorana quasiparticles, which are their own antiparticles and can be created in nanoscale devices similar to transistors. The success of this proposal will lay a foundation for future topological quantum computation which relies on interchanging, or "braiding" of non-Abelian particles. The demonstration of non-Abelian particles will have an impact on science education at the basic textbook level and bring deeper awareness by the society at large of the fundamental laws governing the quantum world. The project will train a graduate student, which develop fundamental and practical skills such as nanofabrication and laboratory techniques at low temperatures. A new course on Quantum Transport aimed at graduate students and senior undergraduates will be developed with a special emphasis on topological effects. To aid in broad dissemination and sharing of scientific knowledge, websites for rapid discussions of new results, as well as for access to raw data and talks will be developed.