CAREER: Novel Electronic and Magnetic Dynamics and Responses in Noncollinear Magnetic Materials

职业：非共线磁性材料中的新型电子和磁动力学及响应

• 批准号: 1945023
• 负责人: Hua Chen
• 金额: $ 45.13万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-06-01 至 2025-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1945023&HistoricalAwards=false
• 关键词: CAREER; Novel; Electronic; Magnetic; Dynamics

NONTECHNICAL SUMMARYThis award supports theoretical and computational research aimed at unraveling the conceptual and practical challenges associated with describing the magnetic order in the so-called noncollinear magnetic materials. Unlike the case for conventional ferromagnets and antiferromagnets, noncollinear magnetic order cannot be visualized as arrays of parallel and antiparallel microscopic magnetic moments. Traditionally noncollinear magnetism has been much less studied than ferromagnetism and anti-ferromagnetism, and has had limited applications. However, recently several noncollinear magnetic metals have been discovered to have surprising properties that could potentially lead to useful electronic and spintronic applications. This cohesive theoretical-computational project aims to identify new principles in the coupled electronic and magnetic dynamics of noncollinear magnets, new and unique response functions to external fields, and to predict new material systems which exhibit noncollinear magnetism.This project contributes to the search for new technological breakthroughs in systems with strong electron interactions. The strongly coupled spin and orbital degrees of freedom in noncollinear magnets may be exploited for efficient spin-charge conversion used in energy harvesting in different scales. The educational component of this project focuses on symmetry and big data, which are overarchingly important in today’s physics and materials science curricula. Through organizing a summer school on Principles and Applications of Symmetry in Magnetism, and redesigning a computational materials physics course to introduce concepts of machine learning, the PI will help local and national undergraduate and graduate students receive necessary exposure to these subjects and integrate them in their professional thinking. Given the multidisciplinary nature of this project, the undergraduate and graduate students involved in the research will also receive the essential training for embracing the “Quantum Leap” challenge in both fundamental science and technology.TECHNICAL SUMMARYNoncollinear magnetic order cannot be visualized as parallel or antiparallel magnetic moments arranged on a crystal lattice, as opposed to ferro- and antiferro-magnetic orders. Recent advancement of the study on such materials in spintronics and magnetotransport has been hindered by conceptual and practical challenges associated with the lack of vector-like order parameters and non-conservation of conduction electrons’ spin. This cohesive theoretical-computational project aims to address these challenges, through the following research thrusts:(1) Computational search for new noncollinear magnets guided by symmetry. Group-theoretic methods and the Landau theory of phase transition will be used to search for new noncollinear magnets in materials science databases beyond the very few known examples. (2) New response functions, functionalities, and experimental probes of noncollinear magnets. A hydrodynamic approach complemented by semiclassical wave-packet theory will be used to elucidate the unique conserved current in noncollinear magnets and its coupling to itinerant electrons. Quantum kinetic theory will be used to identify new response functions such as a counterpart of the giant magnetoresistance but without approximate spin conservation, and the magnetic spin Hall effect in terms of spin density polarization. A theory for using magnetic neutron scattering to detect local orbital magnetization will be formulated. This project contributes to the search for new technological breakthroughs in systems with strong electron correlations. The strongly coupled spin and orbital degrees of freedom in noncollinear magnets may be exploited for efficient spin-charge conversion used in energy harvesting in different scales. The educational component of this project focuses on symmetry and big data, which are overarchingly important in today’s physics and materials science curricula. Through organizing a summer school on Principles and Applications of Symmetry in Magnetism, and redesigning a computational materials physics course to introduce concepts of machine learning, the PI will help local and national undergraduate and graduate students receive necessary exposure to these subjects and integrate them in their professional thinking. Given the multidisciplinary nature of this project, the undergraduate and graduate students involved in the research will also receive the essential training for embracing the “Quantum Leap” challenge in both fundamental science and technology.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.

该奖项支持理论和计算研究，旨在解开与描述所谓的非共线磁性材料中的磁序相关的概念和实践挑战。与传统的铁磁体和反铁磁体的情况不同，非共线磁序不能被视为平行和反平行的微观磁矩阵列。传统上，非共线磁性的研究比铁磁性和反铁磁性少得多，并且应用有限。然而，最近几种非共线磁性金属被发现具有令人惊讶的性质，可能导致有用的电子和自旋电子学应用。本项目是一个理论与计算结合的项目，旨在发现非共线磁体的电磁耦合动力学中的新原理、对外场的新的独特响应函数，并预测具有非共线磁性的新材料系统。本项目为在具有强电子相互作用的系统中寻求新的技术突破做出贡献。非共线磁体中的强耦合自旋和轨道自由度可以用于在不同尺度下用于能量收集的有效自旋-电荷转换。该项目的教育部分侧重于对称性和大数据，这在当今的物理学和材料科学课程中非常重要。通过组织关于磁性对称性原理和应用的暑期学校，并重新设计计算材料物理课程以引入机器学习的概念，PI将帮助当地和国家的本科生和研究生获得必要的接触这些科目，并将其融入他们的专业思维。鉴于该项目的多学科性质，参与研究的本科生和研究生也将接受基础科学和技术方面的“量子飞跃”挑战的必要培训。技术概述非共线磁序不能被视为平行或反平行排列在晶格上的磁矩，而不是铁磁序和反铁磁序。近年来，由于缺乏矢量有序参数和传导电子自旋不守恒，这类材料在自旋电子学和磁输运方面的研究进展受到了概念和实际挑战的阻碍。这个有凝聚力的理论计算项目旨在通过以下研究方向解决这些挑战：（1）对称性指导下的新非共线磁体的计算搜索。群论方法和相变的朗道理论将被用来在材料科学数据库中寻找新的非共线磁体，而不是已知的极少数例子。(2)非共线磁体的新响应函数、功能和实验探针。流体动力学的方法补充半经典波包理论将被用来阐明独特的非共线磁体和它的耦合巡回电子的守恒电流。量子动力学理论将被用来确定新的响应函数，如对应的巨磁电阻，但没有近似的自旋守恒，和磁自旋霍尔效应的自旋密度极化。利用磁中子散射探测局部轨道磁化的理论将被制定。该项目有助于在具有强电子相关性的系统中寻求新的技术突破。非共线磁体中的强耦合自旋和轨道自由度可以用于在不同尺度下用于能量收集的有效自旋-电荷转换。该项目的教育部分侧重于对称性和大数据，这在当今的物理学和材料科学课程中非常重要。通过组织关于磁性对称性原理和应用的暑期学校，并重新设计计算材料物理课程以引入机器学习的概念，PI将帮助当地和国家的本科生和研究生获得必要的接触这些科目，并将其融入他们的专业思维。鉴于该项目的多学科性质，参与研究的本科生和研究生也将接受基础科学和技术方面的“量子飞跃”挑战的必要培训。该奖项反映了NSF的法定使命，并通过使用基金会的智力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

Slowing magnetic relaxation with open-shell diluents

• DOI: 10.1016/j.xcrp.2022.100802
• 发表时间: 2022-03
• 期刊: Cell reports. Physical science
• 作者: Ian P. Moseley;Christopher P. Ard;J. DiVerdi;A. Ozarowski;Hua Chen;Joseph M. Zadrozny

Quantum sensing and imaging of spin‐orbit‐torque‐driven spin dynamics in noncollinear antiferromagnet Mn 3 Sn

非共线反铁磁体 Mn 3 Sn 中自旋轨道扭矩驱动的自旋动力学的量子传感和成像

• DOI: 10.1002/adma.202200327
• 发表时间: 2022
• 期刊: Advanced Materials
• 影响因子: 29.4
• 作者: Yan, Gerald Q.;Li, Senlei;Lu, Hanyi;Huang, Mengqi;Xiao, Yuxuan;Wernert, Luke;Brock, Jeffrey A.;Fullerton, Eric E.;Chen, Hua;Wang, Hailong
• 通讯作者: Wang, Hailong

Discrete degeneracies distinguished by the anomalous Hall effect in a metallic kagome ice compound

• DOI: 10.1038/s41567-023-02307-w
• 发表时间: 2023-11
• 期刊: Nature Physics
• 影响因子: 19.6
• 作者: Kan Zhao;Y. Tokiwa;Hua Chen;P. Gegenwart

Quantum interference in superposed lattices

叠加晶格中的量子干涉

• DOI: 10.1073/pnas.2315787121
• 发表时间: 2024
• 期刊: Proceedings of the National Academy of Sciences
• 作者: Feng, Yejun;Wang, Yishu;Rosenbaum, T. F.;Littlewood, P. B.;Chen, Hua
• 通讯作者: Chen, Hua

Electronic chiralization as an indicator of the anomalous Hall effect in unconventional magnetic systems

• DOI: 10.1103/physrevb.106.024421
• 发表时间: 2022-02
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: Hua Chen