报告题目 (Title)：Novel Properties due to Crystal Symmetry in Topological Superconductor and Altermagnet（交错磁体和拓扑超导体中晶格对称性的奇异性）
报告人 (Speaker)： 刘军伟 教授（香港科技大学）
报告时间 (Time)：2024年10月28日(周一) 14:00
报告地点 (Place)：校本部G601
邀请人(Inviter)：胡晓
主办部门：理学院物理系，量子科技研究院
报告摘要：
I will talk about novel properties due to crystal symmetry in spin-splitting antiferromagnets (AFMs) [Nat. Commun. 12, 2846 (2021)] (also named altermagnet) and in topological superconductor [Nature 633, 71 (2024)].
In spin-splitting AFMs, we propose the crystal-symmetry-paired spin-valley/momentum locking (CSVL), which is enabled by a crystal symmetry and intrinsically exists in AFMs (e.g., V2Se2O, V2Te2O, MnTe and RuO2). CSVL enables feasible controls of spin and valley in AFMs by manipulating the corresponding crystal symmetry. Typically, one can use a strain field to induce net valley polarization/magnetization and use an electric field to generate a noncollinear spin current even without spin-orbit coupling. All the predictions have been confirmed in experiments. These properties have helped us realize the electric readout and 180o deterministic switching of the Néel order in our experimental work [Sci. Adv. 10, eadn0479 (2024)]. Due to these properties, these materials were named as altermagnet [PRX 12, 040501 (2022)].
In topological superconductors, magnetic mirror symmetry can project multiple Majorana zero modes (MZMs) in a single vortex, which allows feasible controls of coupling of MZMs simply using an external field [Nature 633, 71 (2024)].
