报告题目：Light-induced spin splitting in PT-symmetric magnetic and nonmagnetic spin-orbit coupled systems
报 告 人：Zhongbo Yan (严忠波), 中山大学
报告时间：2026年3月24日10：00
报告地点：物理楼W105
内容摘要：Spin splitting is fundamental to a wide range of spin-dependent phenomena. It is primarily induced by two mechanisms: magnetic exchange fields and spin-orbit coupling. Due to fundamental symmetry constraints, spin splitting in collinear magnetic systems—such as ferromagnets and the recently discovered altermagnets—exhibits even parity, meaning it is identical at opposite momenta. In contrast, in non-centrosymmetric non-magnetic systems, spin-orbit coupling preserves time-reversal symmetry, leading to spin splitting with odd parity. In this talk, I will show how light-matter interactions can be used to break key symmetries and, remarkably, interchange the parity of spin splitting induced by these two mechanisms. In the first part, I will discuss antiferromagnetic systems with Dirac band structures and PT symmetry, and demonstrate how circularly polarized light can induce odd-parity spin splitting. In the second part, I will turn to centrosymmetric systems with spin-orbit coupling and show how circularly polarized light can be used to realize even-parity spin splitting.
报告人简介：Zhongbo Yan is currently a Professor at the School of Physics, Sun Yat-sen University. He earned his Bachelor’s degree in 2009 and his Doctorate in 2009 and 2015, both from the University of Science and Technology of China. Between 2015 and 2018, he served as a Postdoctoral Researcher at the Institute for Advanced Study, Tsinghua University. From 2018 to 2024, He held the position of Associate Professor at the School of Physics, Sun Yat-sen University, and was prompted to Full Professor in April 2024. His primary research focus is on the theoretical understanding of topological phases of matter, with recent research interests centering on topological superconductivity and unconventional antiferromagnets. To date, he has authored more than 60 peer-reviewed papers, with most of them published in APS Journals.
