拓扑磁性薄膜材料的多场调控及其相关器件原理研究

拓扑磁性材料是指具有拓扑自旋结构（如斯格明子、涡旋、麦纫）的一类新型磁性功能材料，因具有较低的临界翻转电流密度和空间尺寸在纳米量级上可调等特点，在超高密度磁信息存储领域具有十分重要的应用前景。本项目以具有斯格明子结构的拓扑磁性薄膜/多层膜/复合多层膜为对象，研究拓扑磁性材料的结构（晶体结构、自旋结构）和物性等。拟采用超高真空磁控溅射和分子束外延技术制备高质量多晶/单晶样品，以深紫外光发射电子显微镜和洛伦兹透射电镜两个实空间磁成像技术为主，辅以极化中子反射谱仪，研究斯格明子结构的生成、湮灭及其在多场调控作用下的演变行为，探索以此为核心材料的新型自旋电子学器件工作原理。本项目以高质量拓扑磁性薄膜材料的制备和自旋结构表征为核心研究内容，重点解决拓扑磁性薄膜在材料制备、自旋结构表征、物性研究等方面的材料和物理问题，以及新型自旋电子学器件在结构设计、材料优化、微纳米加工和器件原理上的关键技术问题。

Topological magnetic materials, a new type of magnetic materials with topological spin structures (such as skyrmion, vortex, and meron), exhibit great potential applications in ultra-high density magnetic information storage mainly because of lower critical density of magnetization switch and adjustable size at nanoscale. In this project, the structures (crystal and spin structures) and physical properties of the topological magnetic materials (including magnetic thin films, multilayers, and composite multilayers) will be investigated. The UHV magnetron sputtering and MBE techniques will be used to deposit high quality polycrystalline and single crystal films, and the topological spin structures will be characterized by real space imaging techniques such as the photo emission electron microscopy (PEEM) excited by deep ultra violet (DUV) laser and Lorentz transmission electron microscopy (LTEM), together with polarized neutron reflectometry in the China Spallation Neutron Source (CSNS). The focus will be given on the creation and annihilation of skyrmions, and their behavior under the multi-fields, in order to explore the working principles of related spintronic devices based on the topological magnetic materials. The main issues in this project include the deposition of high quality topological magnetic films and the characterization of topological spin structures, with a focus to solve the key challenges both from the materials and physics about the materials synthesis, spin structures characterization, and the physical properties, and to solve the technical issues about the structure design, materials optimization, micro/nanoscale fabrication, and working principles of related spintronic devices.