CAREER: Monostructural Topological Spin-Insulatronics

非技术总结这个职业奖项支持发现和理解新物理的综合研究和教育努力，使电子设备能够有效地运行，而不会产生不必要的废热。电子设备的小型化对未来技术的进步至关重要。然而，在纳米尺度下，控制效率低、热量飙升和集成的复杂性阻碍了进一步的进展。由于磁性拓扑材料独特的物理特性，最近的发现带来了从根本上解决这些问题的令人兴奋的机会。本项目针对低耗散器件的迫切需求，通过对新兴拓扑材料微观物理的探讨，及时展开研究，旨在为具有(理论)100%功率转换和无散热特性的非耗散器件奠定坚实的物理基础。此外，该项目探索了传统的基于自旋的电子学的变革性变化，使得单个材料单元本身可以同时用作驱动器和振荡器，从而消除了开发复杂的异质结构和界面的需要。这些引人注目的特性得到了交织在一起的电磁结构背后耐人寻味的物理学的支持，在创造颠覆性技术方面具有潜力，甚至可能给现代计算机的基本架构带来革命性的变化。该研究项目还得到了为理论研究培训研究生和本科生的教育活动的补充。国际物理学会将举办一个名为“凝聚态物质”的专题研讨会，以培养不同背景的本科生对凝聚态物理的好奇心，让他们有更多机会接触最新发现和介绍凝聚态物理。PI还将开发一门新的本科课程，即数学编程，以解决物理科学和工程中的实际问题。这一职业奖资助理论研究和教育活动，以实现使用单一磁性材料的非耗散自旋电子学，这种材料可以在不依赖外国部件的情况下自动驱动。传统的磁电控制范例包括工程异质结构，其中磁动力学由磁性材料外部的电荷电流产生的自旋角动量控制。由于抑制了界面自旋转移和不可避免的焦耳加热效应，这样的设置在实现其目的方面是极其低效的。Pi和他的团队追求一种新的自旋电子学范式，从理论上看，这种自旋电子学基于单一结构系统(即单一材料平台)，没有界面，没有焦耳加热。该项目致力于揭开拓扑电子和磁动力学之间错综复杂的相互作用的微观起源，这些相互作用是由内在磁性拓扑绝缘体和其他奇异物质相中的自旋-轨道相互作用以及其他相关自由度实现的。该项目试图量化由纯电压驱动的非平凡的自旋轨道扭矩、随之而来的动力学后果以及基本的对称性原理。除了深入了解单结构自旋电子学史无前例的物理行为外，该项目还寻求做出可通过实验验证的预测，并为适当的实验设计开发一个理论工具箱。该奖项还支持教育活动，包括指导研究生，并为本科生提供独特的机会，让他们在早期阶段参与真正的研究。此外，国际物理学会将举办一个名为“凝聚态物质”的专题研讨会，以培养不同背景的本科生对凝聚态物理的好奇心，让他们有更多机会接触最新发现和介绍凝聚态物理。PI还将在高年级本科生水平开发一门新课程，教授使用数学软件解决物理科学和工程问题的技能。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。

NONTECHNICAL SUMMARY This CAREER award supports integrated research and education endeavors to discover and understand new physics enabling electronic devices to operate efficiently without incurring undesirable waste heat. Miniaturization of electronic devices is essential to the advancement of future technology. Down to the nanometer scale, however, further progress is hurdled by the low control efficiency, soaring heat, and complexity of integration. Recent discoveries of magnetic topological materials bring about exciting opportunities to fundamentally address these problems, thanks to their unique physical characteristics. This project conducts a timely investigation in response to the pressing need for low-dissipation devices by inquiring into the microscopic physics of the emerging classes of topological materials, intending to lay a solid physical foundation for non-dissipative devices featuring a (theoretical) 100% power conversion and vanishing heat production. In addition, the project explores a transformative alternation of the conventional spin-based electronics, such that a single material unit on its own can function as both driver and oscillator, hence obviating the need to develop complex heterostructures and interfaces. These compelling properties, bolstered by the intriguing physics behind the intertwined electronic and magnetic structures, hold potential in creating disruptive technology and could even revolutionize the basic architecture of modern computers.The research project is complemented by educational activities to train both graduate and undergraduate students for theoretical research. The PI will organize a special seminar named “Condensed Matters Matter” targeting undergraduate students of diverse backgrounds to nurture their curiosity in condensed matter physics with an accessible level of introduction and an enhanced exposure to the latest discoveries. The PI will also develop a new undergraduate course on MATHEMATICA programming for solving real problems in physical sciences and engineering. TECHNICAL SUMMARY This CAREER award funds theoretical research and educational activities to achieve non-dissipative spintronics using a single magnetic material which can drive itself without relying on foreign components. Traditional paradigms of electrical control of magnetism involve engineered heterostructures in which magnetic dynamics is controlled by spin angular momenta generated from charge currents outside of the magnetic material. Such a setup is extremely inefficient in serving its purpose because of the inhibited interfacial spin transfer and the inevitable Joule heating effect. The PI and his team pursue a new paradigm of spintronics based on monostructural systems (i.e., single material platforms) free of interfaces and devoid of Joule heating from a theoretical perspective. The project strives to unravel the microscopic origins of the intricate interplay between topological electrons and magnetic dynamics enabled by the spin-orbit interactions, among other relevant degrees of freedom, in intrinsic magnetic topological insulators and other exotic phases of matter. The project seeks to quantify the non-trivial spin-orbit torques driven by pure voltages, the dynamical consequences that follow, and the underlying symmetry principles. Besides establishing an in-depth understanding of the unprecedented physical behavior of monostructural spintronics, the project also seeks to make experimentally verifiable predictions and develop a theoretical toolbox for proper experimental designs. This award also supports educational activities which include mentoring graduate students and providing unique opportunities for undergraduate students to participate in real research at an early stage. In addition, the PI will organize a special seminar named “Condensed Matters Matter” targeting undergraduate students of diverse backgrounds to nurture their curiosity in condensed matter physics with an accessible level of introduction and an enhanced exposure to the latest discoveries. The PI will also develop a new course at senior undergraduate level to teach problem-solving skills in physical sciences and engineering using MATHEMATICA software.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.