Localizing and Manipulating Exotic Quasiparticles in Quantum Hall Antidots

非技术摘要：在固态结构中，量子信息可以根据量子态的性质进行存储和处理。这个项目研究二维原子晶体中的亚微米直径的孔，被称为“解毒剂”，其中量子态可以具有与电子非常不同的有用属性，包括分数电荷和统计。这种状态潜在地允许强大的量子信息应用，并可用于形成人造分子。该项目将理论和实验相结合，在反点结构中创建和操纵量子态，并可能导致新量子比特的发展。这项研究的技术方面结合了材料科学、纳米技术、电子学、低温学、理论凝聚态物理和量子信息，并将为参与该项目的学生提供一个独特的机会，获得所有这些领域的经验，并形成下一代“量子智能”劳动力。该项目还计划开发一个在线、可免费获取的软件工具包--“任意子的世界”，让公众对该项目核心物理的各个方面有一个直观的了解。技术摘要：二维电子系统具有奇异的量子霍尔态，包括支持阿贝尔和非阿贝尔任意子的分数量子霍尔态，以及双层量子霍尔态系统中的激子态。能够局域化和操纵这些量子态的准粒子激发有助于研究强相互作用系统，并有可能导致基于其非平凡拓扑性质的新型量子器件的出现。本项目研究了量子霍尔准粒子在石墨烯及其双层中实现的QH解点上的局域化和操纵。在这种方法中，拓扑保护的QH边缘模被构造成离散的限制环，这些环将携带潜在不可压缩QH液体特征的QH准粒子局部化。该项目探索：1)阿贝尔任意子的稳健定位，并了解单个QH解毒剂的退相干和其他基本物理元素；2)非阿贝尔任意子和激子准粒子在单个解毒剂上的定位；3)将解毒剂耦合到多个反义点结构中，并通过三重反义点结构演示了任意子交换和编织在直流传输中的作用。量子门的QH反点方法是基于单个拓扑激发的绝热转移，这是准粒子交换统计的基础。这项研究促进了对局域准粒子的相关电子系统和交换/编织特性的理解，并应该提供对拓扑编织中量子相干稳定性的直接洞察。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Nontechnical Abstract:In solid-state structures, quantum information can be stored and processed based on properties of quantum states. This project studies sub-micrometer diameter holes in two-dimensional atomic crystals, called "antidots", where the quantum states can have useful properties very different from those of electrons, including fractional charge and statistics. Such states potentially allow robust quantum information applications, and can be used to form artificial molecules. This project combines theoretical and experimental efforts to create and manipulate quantum states in antidot structures, and it could lead to the development of novel qubits. The technical aspects of this research combine material science, nanotechnology, electronics, cryogenics, theoretical condensed matter physics, and quantum information, and will provide students involved in the project with a unique opportunity to obtain experience in all these fields, and form the next generation of a “quantum-smart” workforce. The project also plans to develop an online, freely accessible software kit, “The World of Anyons”, to bring to the public an intuitive understanding of all aspects of the physics at the heart of this project. Technical Abstract:Two-dimensional (2D) electron systems host exotic quantum Hall (QH) states, including fractional QH states supporting abelian and non-abelian anyons, and excitonic states in double-layer QH systems. Being able to localize and manipulate quasiparticle excitations of these quantum states facilitates the study of the strongly interacting systems, and potentially leads to novel quantum devices which operate based on their non-trivial topological properties. This project studies the localization and manipulation of quantum Hall quasiparticles on QH antidots realized in graphene and its double-layers. In this approach, topologically protected QH edge modes are structured into discrete confining loops that localize the QH quasiparticles which carry the characteristics of the underlying incompressible QH liquid. This project explores: 1) robust localization of abelian anyons and understanding the decoherence and other basic physics elements of the individual QH antidots; 2) localization of non-abelian anyons and excitonic quasiparticles on individual antidots; 3) coupling of the antidots into the multi-antidot structures, and demonstration of anyon exchange and braiding in DC transport through a triple-antidot structure. The QH antidot approach to quantum gates is based on the adiabatic transfer of the individual topological excitations, which is the basis for the quasiparticle exchange statistics. This study advances the understanding of correlated electron systems and exchange/braiding properties of localized quasiparticles, and should provide direct insight into the stability of quantum coherence in topological braiding.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.