Electron Spin Effects in Semiconductor Nanostructure: Magnetism and Topology

摘要：本课题主要研究磁学与拓扑学之间的联系，这是近年来半导体物理学和量子力学的一个重要研究前沿。然而，设计和合成表现出这种联系的量子材料是一个重大挑战。因此，该项目的具体目标是设计和合成新的弹性材料，在这些材料中可以研究这种联系，并利用这些材料实现变革性的发现。这些发现可能会在新兴的量子计算领域产生新的科学和技术。该项目将使用分子束外延，这是一种可以逐个原子构建材料的工具。这使得具有新功能的材料设计可以在当代和新兴技术中使用。该研究组将合成具有可控磁性质的高质量半导体材料。该项目的另一部分将包括研究以周期性结构堆叠的半导体材料的特性。不同层之间的耦合可能导致完全不同的功能，这是单独使用任何一种材料都不可能实现的。该项目可能为消耗极低能量的下一代量子计算设备和数据存储设备提供重要的解决方案。该项目还将培训学生，为他们提供必要的技能，为国家劳动力提供支持和推进量子计算和数据存储新技术的技能。技术摘要：该项目涉及半导体中磁性和拓扑之间的相互作用，这是一个学科组合，已经产生了直接影响量子和自旋电子器件物理学的令人兴奋的发现。该项目的具体目标是利用微调旋钮，如应变，异质结构和亚稳相合成，使精密分子束外延成为可能，旨在发展强大的自旋电子拓扑相。拟议的目标是通过解决两个目标来实现的。第一个目标是利用二维III-Mn-V界面的垂直磁各向异性来实现温度弹性量子反常霍尔效应。第二个目标是在由拓扑绝缘体和普通绝缘体堆叠组成的磁性拓扑超晶格中设计物质的新涌现量子相，其中一个是磁性的。通过结合材料开发、光学探针和电子表征工具方面的互补专业知识，该团队有能力在推进当前对磁性拓扑相的理解和加强其对环境扰动的恢复能力方面取得重大突破。该项目将这些研究目标与强大的教育组成部分相结合，包括通过研究各种与半导体和量子技术相关的工具进行直接培训，并推出一门专注于凝聚态物理拓扑相的课程。该奖项反映了美国国家科学基金会的法定使命，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。

Non Technical Abstract:This project involves investigating the connection between the science of magnetism and topology, which has recently become a major research frontier of semiconductor physics as well as quantum mechanics. The design and synthesis of quantum materials exhibiting this connection is, however, a major challenge. The specific goal of this project is therefore to design and synthesize new resilient materials in which this connection can be studied, and to achieve transformative discoveries using those materials. Those discoveries could result in new science and technology of interest in the emerging field of quantum computing. The project will use molecular beam epitaxy, which is a tool by which materials can be constructed atom-by-atom. This allows the design of materials with new functionalities that can be utilized in contemporary and emerging technologies. This research team will synthesize high-quality semiconductor materials with controllable magnetic properties. Another part of the project will include investigating the properties of semiconductor materials which have been stacked in periodic structures. The coupling between the different layers could lead to completely different functionalities not possible from either material separately. The project could potentially provide important solutions to next-generation devices for quantum computing and data storage devices that consume very low energy. This project will also train students by providing them with a skill set necessary to supply the nation's workforce to support and advance new technologies of quantum computing and data storage.Technical Abstract: The project involves the interplay between magnetism and topology in semiconductors, a combination of disciplines that has already delivered exciting discoveries which directly impact quantum and spintronic device physics. The specific goals of this project are to utilize tuning knobs, such as strain, heterostructuring and metastable phase synthesis, made possible by precision molecular beam epitaxy, aimed at developing robust spintronic topological phases. The proposed goals are reached by tackling two objectives. The first objective aims to harness perpendicular magnetic anisotropy in two-dimensional III-Mn-V interfaces to achieve a temperature-resilient quantum anomalous Hall effect. The second objective aims to engineer new emergent quantum phases of matter in magnetic topological superlattices consisting of stacks of topological and normal insulators, one of which is magnetic. By combining complementary expertise in material development, optical probes, and electronic characterization tools, the team has the ability to achieve major breakthroughs toward advancing current understanding of magnetic topological phases and toward strengthening their resilience to environmental perturbations. The project synergizes those research objectives with a strong educational component that includes direct training by research on a variety of tools relevant to semiconductor and quantum technologies, and launching a course focused on topological phases in condensed matter physics.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.