Localizing and Manipulating Exotic Quasiparticles in Quantum Hall Antidots

摘要：在固体结构中，量子信息可以根据量子态的性质进行存储和处理。该项目研究二维原子晶体中亚微米直径的空穴，称为“反点”，其中量子态可能具有与电子非常不同的有用特性，包括分数电荷和统计。这种状态可能允许强大的量子信息应用，并可用于形成人工分子。这个项目结合了理论和实验的努力来创造和操纵反点结构中的量子态，它可能会导致新型量子比特的发展。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，以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的、免费的软件工具包，“任何人的世界”，让公众直观地了解这个项目核心的物理学的各个方面。技术摘要：二维（2D）电子系统拥有奇异量子霍尔（QH）态，包括支持阿贝尔和非阿贝尔任意子的分数阶QH态，以及双层QH系统中的激子态。能够定位和操纵这些量子态的准粒子激发有助于对强相互作用系统的研究，并有可能导致基于其非琐碎拓扑性质操作的新型量子器件。本项目研究了量子霍尔准粒子在石墨烯及其双层QH反点上的定位和操纵。在这种方法中，拓扑保护的QH边缘模式被构造成离散的约束环，这些约束环定位了具有底层不可压缩QH液体特征的QH准粒子。本项目探索：1)阿贝尔任意子的鲁棒定位，理解单个QH反点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反点上的局域化；3)将反点耦合到多反点结构中，并通过三反点结构证明了直流输运中的任意子交换和编织。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。该研究促进了对相关电子系统和局域准粒子交换/编织特性的理解，并为拓扑编织中量子相干性的稳定性提供了直接的见解。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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.