题目：Unconventional magnetism

报告人：吴从军 

邀请人：游建强、王孝群

时间：2024年12月11日（周三）下午15:30

地点：紫金港校区海纳苑8幢215报告厅

摘要：

We propose a conceptually new mechanism for the spontaneous generation of spin-orbit coupling based on itinerant Fermi surface instabilities, which goes beyond the relativistic version and can exhibit the so-called altermagnetism-type symmetries. The ordered phases are classified into two classes, dubbed the alpha and beta-phases, respectively. The Fermi surfaces in the alpha phases exhibit spontaneous anisotropic distortions, which are the electronic nematic phases augmented by the spin degree of freedom. The beta-phases remain isotropic and develop nontrivial spin-texture configurations in momentum space – exhibiting various types of spin-orbit coupling. Possible directions for experimentally realizing these phases in transition metal oxides and rare earth compounds, and detections including neutron scattering,  optical methods, and transport methods are discussed.  

Ref:

1) Congjun Wu, and Shou-Cheng Zhang, Dynamic generation of spin-orbit coupling, Phys. Rev. Lett. 93, 36403(2004).

2) Congjun Wu, Kai Sun, Eduardo Fradkin, and Shou-Cheng Zhang, Fermi liquid instabilities in the spin channel, Phys. Rev. B 75, 115103 (2007).

3) Congjun Wu, “Symmetry principle in condensed matter physics (I),” A Festschrift in Honor of the C N Yang Centenary，Scientific Papers, page 413-473 (2022).

个人简介：

Congjun Wu received his Ph.D. in physics from Stanford University in 2005 and did his postdoctoral research at the Kavli Institute for Theoretical Physics, University of California, Santa Barbara, from 2005 to 2007. He became an Assistant Professor in the Department of Physics at the University of California, San Diego in 2007, an Associate Professor in 2011, and a Professor in 2017. In 2021, he became a Chair Professor at School of Science, Westlake University.  He was selected as a New Cornerstone Investigator in 2023, elected to a Fellow of American Physical Society in 2018, and awarded the Sloan Research fellowship in 2008. His research interests are exploring new states of matter and reveling their organizing principles, including quantum magnetism, superconductivity, topological states, mathematical physics, and the numerical method of quantum Monte Carlo simulations.