Spin Splitting in Unconventional Magnets

Speaker: Dr. Seung Hun Lee

TQI Postdoctoral Fellow, The University of Texas at Austin

Distinguished Seminar Series Sponsored by the Texas Quantum Institute

Zoom Meeting Details:
https://utexas.zoom.us/j/87817158581

Meeting ID: 878 1715 8581

Passcode: TQI-FAC

Magnetism is conventionally described by ferromagnets, where aligned spins produce a net magnetization, and antiferromagnets, where opposing spins cancel each other. In ferromagnets, spin degeneracy is lifted because time-reversal symmetry is broken, whereas in antiferromagnets, it is often preserved. Recently, this view has expanded with the discovery of unconventional magnets—materials that exhibit no net magnetization yet lift the spin degeneracy of electronic states.
In this talk, Dr. Lee will discuss how real-space spin configurations in unconventional magnets lift spin degeneracy and generate momentum-dependent spin textures, even in the absence of spin–orbit coupling. These momentum-space spin textures provide two key insights into their electronic behavior. First, they explain the appearance of spin-degenerate nodes in unconventional magnets, even when the system lacks specific spin–space group symmetries that would normally protect such nodes. Second, they play a crucial role in determining the pairing symmetry of superconducting states, offering a natural route to spin-triplet superconductivity.

Seung Hun Lee received his Ph.D. in Physics from Seoul National University under the supervision of Professor Bohm-Jung Yang. Dr. Lee joined Professor Junyeong Ahn’s theory group at The University of Texas Austin as a postdoctoral researcher in April 2025 and began the TQI Postdoctoral Fellowship this September.