报告题目 (Title)：Chirality and Kinetomagnetism

报告人 (Speaker)：Prof. Sang-Wook Cheong (Rutgers, The State University of New Jersey, USA)

报告时间 (Time)：2024年6月21日（周五）8:30-13:00

报告地点 (Place)：校本部 D413

邀请人 (Inviter)：任伟 教授

主办部门：理学院物理系

报告摘要：

Chirality, which arises from the breaking of mirror symmetries combined with any spatial rotations, plays a ubiquitous role in a wide range of phenomena, from the DNA functionality, vine climbing to the piezoelectricity of quartz crystals. It's important to note that chirality does not necessarily involve a screw-like twisting, and magnetic chirality means chirality in spin ordered states or mesoscopic spin textures. Despite being mathematically well-defined, the term "chirality" has been extensively used, often in confusing ways, in recent years. In steady states, chirality (C) does not change with time-reversal operation, while chirality prime (C') denotes the breaking of time-reversal symmetry in addition to broken all mirror symmetries, combined with any spatial rotations. Various examples of magnetic chirality and chirality prime and their emergent phenomena, such as self-inductance, directional nonreciprocity in magnetic fields, currentinduced magnetization, chirality-selective spin-polarized current, Schwinger scattering, magneto-optical Kerr effect, linear magnetoelectricity, and chiral tunneling will be discussed. Many of these phenomena can be understood with one hypothesis on “kinetomagnetism in chiral systems” that I will present. Some of these exotic phenomena have been recently observed, while many others require experimental confirmation in the future.

报告人简介：

Prof. Sang-Wook Cheong studied mathematics at Seoul National University and physics at the University of California, Los Angeles. He acquired his Ph. D. from UCLA in 1989 while most of his research was performed at Los Alamos National Laboratory. He became a postdoctoral fellow at Bell Laboratories, AT&T (1989-1991) and then was appointed a Member of Technical Staff. In 1997 he became a tenured full professor at Rutgers University, while maintaining part-time employment at Bell Laboratories until 2001. He became a distinguished professor at Rutgers in 2001, and in 2005 became the founding director of the Rutgers Center for Emergent Materials (RCEM). In 2011 he was appointed Board of Governors Professor at Rutgers. In 2017 he was appointed Henry Rutgers Professor, and became the founding director of the center for Quantum Materials Synthesis (cQMS), supported by Gordon & Betty Moore Foundation and Rutgers. Cheong’s research activities focus on studies of mesoscopic self-organization in solids, including the nanoscale charge stripe formation, mesoscopic electronic phase separation in mixed-valent transition etal oxides, and the formation of topological vortex domains in improper ferroelectrics. The formation and topology of these self-organized textures can be synergistically relevant to other areas of science such as mathematics (graph theory) and even cosmology. He has also made significant contributions to the research field of enhanced functionalities in complex materials originating from collective correlations such as colossal magnetoresistive and colossal magnetoelectric effects.