CAREER: Magnetic topological phases in dissipative systems

该奖项的部分资金来自《2021年美国救援计划法案》(公法117-2)。非技术概述该奖项支持理论研究和教育，以促进对磁性材料中拓扑相的基本理解。拓扑学是数学的一个分支，研究不能通过扭曲系统来改变的性质。拓扑学在凝聚态系统中的应用导致了许多新的现象和拓扑材料的发现，例如拓扑绝缘体。这些材料大部分是绝缘体，因此不导电。然而，他们在他们的表面和角落进行着传导。拓扑学要求无论材料多么无序，这些“边缘状态”都是存在的。虽然过去的研究工作主要集中在系统能量守恒的拓扑阶段，但近年来出现了一系列关于系统的研究，在这些系统中，由于与环境的重大相互作用，能量可能获得或损失。PI旨在扩展这一新建立的理论框架，以解决磁系统的拓扑性质。拓扑磁性材料已经被提出作为许多技术应用的构建块，并可能作为观察新的耗散拓扑现象的固态平台。然而，利用它们的潜力需要更好地了解它们的拓扑结构和它们与周围晶体环境的无处不在的耗散相互作用之间的相互作用。PI将探索耗散拓扑磁现象的现实潜在平台，并将开发新的理论技术来提供预测，以指导当前和未来的实验探索。除了指导和培训参与这项研究的研究生和本科生外，PI还计划开发一门关于自旋电子学领域最新发展的教学课程。作为波士顿学院女性物理学会的联合创始人，PI将继续为本科生和研究生女性创造新的网络机会。此外，PI的目标是为来自不发达国家的初级研究人员开发一个研讨会。技术总结这个职业奖项支持理论研究和教育，以促进对耗散系统中磁性拓扑相的基本理解。这个项目的目的是在非厄米特拓扑理论的框架内研究磁性拓扑相，并探索产生拓扑上非平凡的磁振子带的自旋无关机制。具体地说，该项目由三项密切相关的研究工作组成：1)调查拓扑保护的非厄米磁振子边态的基本性质，探索实验上可行的平台，以实现和探测不受非线性自旋体动力学阻碍的拓扑磁振子输运；2)确定磁系统中体边对应破裂的必要成分，并开发新的分析技术来预测磁集肤效应的实验观察值；3)探索拓扑保护的非厄米磁非极化子边态在离子晶体中的出现和输运性质。除了指导和培训参与这项研究的研究生和本科生外，PI还计划开发一门研究生水平的教学课程，介绍自旋电子学领域的最新发展。作为波士顿学院女性物理学会的联合创始人，PI将继续为本科生和研究生女性创造新的网络机会。此外，PI的目标是为来自不发达国家的初级研究人员开发一个研讨会。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。

This award is funded in part under the American Rescue Plan Act of 2021 (Public Law 117-2).NONTECHNICAL SUMMARY This CAREER award supports theoretical research and education to advance the fundamental understanding of topological phases in magnetic materials. Topology is a branch of mathematics that addresses properties that cannot be altered by distorting a system. The application of topology to condensed matter systems has led to the discovery of many new phenomena and topological materials, for example topological insulators. The bulk of these materials are insulators, and so, do not conduct electricity. However, they are conducting on their surfaces and corners. Topology requires that these "edge states" are present no matter how disordered the material might be. While past research efforts have been focused on topological phases in which the system’s energy is conserved, recent years have witnessed a burst of research on systems where, owing to significant interactions with the environment, energy may be gained or lost. The PI aims to expand this newly established theoretical framework to address the topological properties of magnetic systems. Topological magnetic materials have been proposed as building blocks for numerous technological applications and might serve as solid-state platforms for observing novel dissipative topological phenomena. However, harnessing their potential requires a better understanding of the interplay between their topology and their ubiquitous dissipative interactions with the surrounding crystalline environment. The PI will explore realistic potential platforms of dissipative topological magnetic phenomena and will develop new theoretical techniques to provide predictions that can guide current and future experimental explorations. In addition to mentoring and training graduate and undergraduate students participating in this research, the PI plans to develop a pedagogical course on the recent developments in the field of spintronics. As co-founder of the Women in Physics Society at Boston College, the PI will continue to create new networking opportunities for undergraduate and graduate women. Furthermore, the PI aims to develop a workshop for junior researchers from underdeveloped countries.TECHNICAL SUMMARY This CAREER award supports theoretical research and education to advance the fundamental understanding of magnetic topological phases in dissipative systems. This project is aimed to investigate magnetic topological phases within the framework of non-Hermitian topological theories and to explore spin-independent mechanisms for the generation of topologically nontrivial magnon bands. Specifically, the project consists of three closely related research efforts: 1) investigating the fundamental properties of topologically-protected non-Hermitian magnon edge states and exploring experimentally feasible platforms to realize and probe topological magnon transport unhindered by nonlinear spin bulk dynamics; 2) identifying the essential ingredients for the breakdown of the bulk-edge correspondence in magnetic systems and developing new analytical techniques to predict experimental observables of the magnetic skin effect; 3) exploring the emergence and the transport properties of topologically-protected non-Hermitian magnon-polaron edge states in ionic crystals. In addition to mentoring and training graduate and undergraduate students participating in this research, the PI plans to develop a pedagogical course at the graduate level on the recent developments in the field of spintronics. As co-founder of the Women in Physics Society at Boston College, the PI will continue to create new networking opportunities for undergraduate and graduate women. Furthermore, the PI aims to develop a workshop for junior researchers from underdeveloped countries.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.