Topological order and Anyons in and out of Equilibrium

拓扑序和平衡态内外的任意子

• 批准号: 2220703
• 负责人: Ashvin Vishwanath
• 金额: $ 56万
• 依托单位: Harvard University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2220703&HistoricalAwards=false
• 关键词: Topological; order; Anyons; out; Equilibrium

NONTECHNICAL SUMMARYThis award supports theoretical research into the quantum physics of many interacting particles, often referred to as quantum matter. These systems are the gateway to a rich and promising scientific arena, given the extraordinary ability of quantum particles to remain tied to one another even when separated, a property termed quantum entanglement. Realizations of quantum matter are everywhere, ranging from electrons in crystals to engineered platforms consisting of arrays of atoms. In this project, the PI and his team will explore strategies to create highly entangled quantum matter and to identify the features that characterize them. A particularly interesting subclass is topological matter, in which new excitations called "anyons" arise that are entirely distinct from the individual components that go into building them. Such excitations are speculated to lead to novel material properties and capabilities in quantum information. The PI will explore new arenas to realize topological states, including in artificial materials created by stacking atomically thin sheets and by driving matter with external fields far from thermal equilibrium. The education of the next generation of junior scientists is a key part of this project. Undergraduate and graduate students will be exposed to modern ideas of quantum condensed matter physics through coursework as well as research collaborations. This will contribute to the US workforce in fundamental science and quantum technologies. The research outcomes and course materials developed throughout the course of this project will be widely disseminated via non-technical summaries, pedagogical lecture notes, as well as seminars, colloquia and lecture series at scientific schools for young researchers.TECHNICAL SUMMARYThis award supports theoretical research on quantum states of matter with novel excitations stabilized by topology, to identify their experimental signatures and to enable their realizations in solids and ultracold quantum gases. While a glimpse of topological order and the associated anyon excitations have previously appeared in the fractional quantum Hall effect, this award will focus on realizing these and other topological states in a wider set of systems and in the absence of strong magnetic fields. The topological character of these states make their detection a challenge. The PI will study models of electronic and cold atom systems that are both promising platforms for topological orders and allow for measurements that can unequivocally point to their realization. Moving beyond ground states, driven systems harboring anyon excitations exhibit an extra layer of complexity and richness, and furnish an alternate route to stabilizing topological orders. The PI will explore topological orders driven far from equilibrium, due to external drives and/or measurements as well as out-of-equilibrium routes to realizing new states, including ones with non-Abelian anyon excitations.This award also supports the training of the next generation of researchers in modern theoretical physics, via research and coursework. New course material at the graduate level will be developed, which will incorporate insights gleaned from research. The research outcomes and course materials developed throughout the course of this project will be widely disseminated via non-technical summaries, pedagogical lecture notes, as well as seminars, colloquia and lecture series at scientific schools for young researchers.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.

非技术总结该奖项支持对许多相互作用粒子的量子物理学的理论研究，通常被称为量子物质。这些系统是通往一个丰富而有前途的科学竞技场的大门，因为量子粒子具有非凡的能力，即使在分离时也能保持相互联系，这种特性称为量子纠缠。量子物质的实现无处不在，从晶体中的电子到由原子阵列组成的工程平台。在这个项目中，PI和他的团队将探索创造高度纠缠量子物质的策略，并识别表征它们的特征。一个特别有趣的子类是拓扑物质，其中出现了称为“任意子”的新激发，它们与构建它们的单个组件完全不同。据推测，这种激发将导致量子信息中的新材料特性和能力。PI将探索新的领域来实现拓扑状态，包括通过堆叠原子薄片和通过远离热平衡的外部场驱动物质而创建的人造材料。下一代年轻科学家的教育是该项目的关键部分。本科生和研究生将通过课程和研究合作接触到量子凝聚态物理学的现代思想。这将有助于美国在基础科学和量子技术方面的劳动力。在整个项目过程中开发的研究成果和课程材料将通过非技术摘要、教学讲义以及科学学校为年轻研究人员举办的研讨会、座谈会和系列讲座广泛传播。技术摘要该奖项支持对具有拓扑稳定的新颖激发的物质量子态的理论研究，以确定它们的实验特征，并使它们能够在固体和超冷量子气体中实现。虽然拓扑秩序和相关的任意子激发的一瞥以前已经出现在分数量子霍尔效应中，但该奖项将专注于在更广泛的系统中以及在没有强磁场的情况下实现这些和其他拓扑状态。这些状态的拓扑特征使它们的检测成为一个挑战。PI将研究电子和冷原子系统的模型，这些模型都是有前途的拓扑秩序平台，并允许可以明确指出其实现的测量。超越基态，包含任意子激发的驱动系统表现出额外的复杂性和丰富性，并提供了稳定拓扑秩序的替代途径。PI将探索由于外部驱动和/或测量而远离平衡的拓扑序，以及实现新状态的非平衡路线，包括具有非阿贝尔任意子激发的路线。该奖项还通过研究和课程支持现代理论物理学的下一代研究人员的培训。将编制研究生一级的新教材，其中将纳入从研究中获得的见解。在本项目的整个过程中开发的研究成果和课程材料将通过非技术摘要、教学讲义以及在科学学校为年轻研究人员举办的研讨会、座谈会和系列讲座广泛传播。该奖项反映了NSF的法定使命，并被认为值得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来支持。

项目成果

Many-body ground states from decomposition of ideal higher Chern bands: Applications to chirally twisted graphene multilayers

• DOI: 10.1103/physrevresearch.5.023166
• 发表时间: 2023-06-01
• 期刊: PHYSICAL REVIEW RESEARCH
• 影响因子: 4.2
• 作者: Dong, Junkai;Ledwith, Patrick J.;Vishwanath, Ashvin
• 通讯作者: Vishwanath, Ashvin

XY* Transition and Extraordinary Boundary Criticality from Fractional Exciton Condensation in Quantum Hall Bilayer

量子霍尔双层中分数激子凝聚的 XY* 跃迁和非凡边界临界点

• DOI: 10.1103/physrevx.13.031023
• 发表时间: 2023
• 期刊: Physical Review X
• 影响因子: 12.5
• 作者: Zhang, Ya-Hui;Zhu, Zheng;Vishwanath, Ashvin
• 通讯作者: Vishwanath, Ashvin