Inviter: 张坚地 研究员 （9454）

Contact: 周发然 副研究员（9677）

Abstract:
The magneto-optical effects are known as an indispensable tool for studying condensed matter physics in quantum materials. In the past, attention has been paid to the linear magneto-optical effects such as Faraday rotation, Kerr rotation, and magnetic circular dichroism. In this talk, I will introduce the nonlinear magneto-optical effect based on the optical second harmonic generation (SHG). In 2019, we found the layered anti-ferromagnetism in CrI3 bilayer leads to a giant nonreciprocal magnetic SHG [Nature 572, 497 (2019)]. Here I will report our latest studies that utilize this powerful effect to elucidate a series of novel magnetic phenomena in 2D magnetic semiconductors, including the magnetic polymorphism and layer-sharing effect [Nat. Mater. 24, 226 (2025)], charge transfer governed interlayer magnetic coupling and symmetry breaking [Nat. Commun. 16, 9498 (2025)], and interlayer-locked antiferromagnetic switching [Nature 650, 340 (2026)].

About the speaker:
吴施伟，复旦大学物理系谢希德特聘教授，现任微纳光子结构教育部重点实验室主任，入选教育部国家高层次人才、上海市优秀学术带头人等。2001年本科毕业于复旦大学物理系；2007年博士毕业于美国加州大学尔湾分校物理与天文系；2007年至2011年在美国劳伦斯伯克利国家实验室从事博士后研究；2011年加入复旦物理系并工作至今。研究方向是低维量子体系的光物理，致力于应用自主创新开发的光学显微方法研究凝聚态物理问题。学术成果以通讯作者发表在Nature、Science及其子刊和PRL等国际知名期刊，SCI他引8000余次，并以第一完成人获得2025年上海市自然科学一等奖。相关技术获授权中国发明专利7项、美国发明专利2项。现作为项目负责人主持“物态调控”重点研发专项项目、基金委重点项目和重大科研仪器研制项目等。