Novel Topological States in Correlated Quantum Systems

相关量子系统中的新颖拓扑态

• 批准号: 1712128
• 负责人: Ying Ran
• 金额: $ 31.5万
• 依托单位: Boston College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-05-01 至 2022-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1712128&HistoricalAwards=false
• 关键词: Novel; Topological; States; Correlated; Quantum

NONTECHNICAL SUMMARYThis award supports theoretical research and education in understanding novel quantum states of matter in solid-state materials. At low temperatures, quantum mechanics can bring materials into states of matter that have no classical analog. Topological states of matter are such novel quantum states of matter, and they exhibit striking new physical properties. For example, charge carriers in some topological states behave as if they were a fraction of an electron, and their properties can be exploited to build robust quantum computers.The thrusts of the research activities include: 1) Developing a new theoretical framework to systematically understand topological states and developing new computational techniques to simulate these states in a reliable fashion. 2) Applying these techniques to investigate topological states and their physical properties in real materials. 3) Developing guiding principles helpful in searching for new topological states in materials.This project will generate knowledge and computational methods needed for advances in quantum material science and quantum technology. The educational activities include developing pedagogical courses, lectures, and journal-club series for undergraduate and graduate students, with emphasis on the new states of matter discovered in modern condensed matter physics. As an outreach activity, an interactive website will be created to disseminate teaching materials and to demonstrate topological phenomena, with the aim of sparking general interest in science and technology.TECHNICAL SUMMARYThis award supports theoretical research and education in understanding topological quantum states of matter. Very rich classes of correlation-driven topological phases have been predicted theoretically; however, the existence of only few of them has been confirmed in real materials. The relevant challenges are the limitations of currently available theoretical and numerical methods for correlated quantum systems, as well as the lack of physical guiding principles to direct the search for many correlated topological states. This project addresses both these challenges.The research activities comprise three main thrusts: 1) The PI will further develop a symmetric tensor network framework and numerical algorithms suitable for investigating correlated topological phases. The tensor network can be viewed as a new language for quantum many-body physics capable of capturing topological properties of quantum states. 2) By applying this framework, the PI will search for model systems that realize correlation-driven topological phases, including models for correlated transition-metal materials. In addition, excitation properties of candidate topological materials will be computed and compared with experiments. 3) The PI will develop symmetry-based guiding principles that are independent of microscopic details, aiding the search for topological states in materials.The research is closely connected to quantum information science and algebraic topology in mathematics, and it could bring new insight in these disciplines. The educational activities include developing pedagogical courses, lectures, and journal-club series for undergraduate and graduate students, with emphasis on the new states of matter discovered in modern condensed matter physics. The PI will develop and maintain an interactive website hosting research and teaching materials, which will include demonstrations of topological phenomena in condensed matter physics and tensor networks.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.

非技术性总结该奖项支持在理解固态材料中物质的新量子态方面的理论研究和教育。在低温下，量子力学可以使材料进入没有经典模拟的物质状态。物质拓扑态就是这样一种新颖的物质量子态，它们表现出惊人的新物理性质。例如，在某些拓扑状态下，电荷载流子的行为就像是电子的一部分，利用它们的性质可以构建强大的量子计算机。研究活动的重点包括：1）发展新的理论框架，系统地理解拓扑状态，并发展新的计算技术，以可靠的方式模拟这些状态。2)应用这些技术研究真实的材料的拓扑态及其物理性质。3)开发有助于寻找材料中新拓扑状态的指导原则。本项目将产生量子材料科学和量子技术进步所需的知识和计算方法。教育活动包括为本科生和研究生开发教学课程，讲座和期刊俱乐部系列，重点是现代凝聚态物理学中发现的新物质状态。作为一项推广活动，将建立一个互动网站，以传播教学材料和演示拓扑现象，目的是激发公众对科学和技术的兴趣。技术概述该奖项支持理解物质拓扑量子态的理论研究和教育。理论上已经预测了非常丰富的相关驱动拓扑相，然而，在真实的材料中，只有少数几种相关驱动拓扑相的存在得到了证实。相关的挑战是目前可用的相关量子系统的理论和数值方法的局限性，以及缺乏物理指导原则来指导许多相关的拓扑状态的搜索。该项目旨在解决这两个挑战。研究活动包括三个主要方面：1）PI将进一步开发对称张量网络框架和适用于研究相关拓扑相位的数值算法。张量网络可以被看作是量子多体物理学的一种新的语言，能够捕捉量子态的拓扑性质。2)通过应用这个框架，PI将搜索实现相关驱动拓扑相的模型系统，包括相关过渡金属材料的模型。此外，候选拓扑材料的激发特性将被计算并与实验进行比较。3)PI将开发独立于微观细节的基于量子力学的指导原则，帮助寻找材料中的拓扑状态。该研究与数学中的量子信息科学和代数拓扑学密切相关，可以为这些学科带来新的见解。教育活动包括为本科生和研究生开发教学课程，讲座和期刊俱乐部系列，重点是现代凝聚态物理学中发现的新物质状态。PI将开发和维护一个交互式网站，用于托管研究和教学材料，其中将包括凝聚态物理和张量网络中拓扑现象的演示。该奖项反映了NSF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。

项目成果

Accessing new magnetic regimes by tuning the ligand spin-orbit coupling in van der Waals magnets

• DOI: 10.1126/sciadv.abb9379
• 发表时间: 2020-07
• 期刊: Science Advances
• 影响因子: 13.6
• 作者: T. Tartaglia;Joseph N. Tang;J. Lado;F. Bahrami;M. Abramchuk;G. McCandless;Meaghan C. Doyle;K. Burch;Ying Ran;J. Chan;F. Tafti

Visualization of bulk and edge photocurrent flow in anisotropic Weyl semimetals

• DOI: 10.1038/s41567-022-01898-0
• 发表时间: 2022-03
• 期刊: Nature Physics
• 影响因子: 19.6
• 作者: Yu-Xuan Wang;Xin-Yue Zhang;Chunhua Li;Xiaohan Yao;Ruihuan Duan;Thomas Graham;Zheng Liu;F. Tafti;D. Broido;Ying Ran;B. Zhou

Engineering chiral topological superconductivity in twisted Ising superconductors

• DOI: 10.1103/physrevb.106.125136
• 发表时间: 2022-06
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Xiao-Pei Hu;Ying Ran