拓扑节线半金属中的RKKY磁相互作用及其相变特性研究

自旋操控是自旋电子学领域的研究核心。RKKY磁相互作用不仅为自旋的操控提供了可能，其信号还可以表征材料的内禀属性，探讨拓扑体系的RKKY磁相互作用对拓扑量子态的理解及其潜在的应用有重要的意义。节线半金属是一种新型拓扑量子材料，其独特的拓扑性质能诱导丰富的磁学特性。本项目以拓扑节线半金属为研究平台，拟开展RKKY磁相互作用的研究，具体内容包括：1）研究节线半金属的拓扑表面态对磁相互作用的影响,深入理解表面态的磁学特性；2）研究节线半金属的拓扑相变与磁相互作用的关联，揭示表征拓扑相变的磁信号；3）研究铁磁/节线半金属/铁磁异质结中磁相互作用的规律，找寻延缓磁相互作用衰减的方法。本项目在深入理解拓扑量子态磁学特性的同时，试图为表面态的探测、相变的鉴定以及磁信号的增强提供新的思路，并为自旋调控及自旋电子器件的开发提供理论支撑。

Spin manipulation is the central research in the field of spintronics. The magnetic RKKY interaction provides a possibility for the spin manipulation, the signatures of which can also reflect the intrinsic properties of materials. Exploring the RKKY interaction in topological systems is of great importance not only for the understanding of topological quantum state but also for its potential application. Nodal-line semimetal is a new type of topological quantum material, and its peculiar topological properties could induce rich magnetic characteristics. In this project, based on the nodal-line semimetal, we aim to explore the magnetic RKKY interaction in different scenarios. The contents are included as follows: 1) Studying the effect of the topological surface state on the RKKY interaction in nodal-line semimetal, and exploring the magnetic properties of the surface state. 2) Studying the relation between the topological phase transition and the RKKY interaction in nodal-line semimetals, and exploring the magnetic signature to identify the topological phase transition. 3) Studying the behavior of the RKKY interaction in FM/nodal-line semimetal/FM heterojunction, and finding new methods to delay the decaying rate of the RKKY interaction. This project will provide deep understanding for the characteristics of topological quantum states. Meanwhile, we anticipate to provide new ways to detect the surface state, characterize the topological phase transition, and enhance the magnetic signal. Moreover, we can offer theoretical foundations for manipulation of the spin degree of freedom, as well as for exploitation of the advanced spintronic devices.