Topological spin textures and Hall effects in chiral magnets
Physics Department, The Ohio State University
Abstract: Skyrmions are topological solitons that were first discussed in quantum field theory in the 1960’s. In recent years, through a series of beautiful experimental developments, they have become of great relevance to condensed matter systems, especially in chiral magnetic materials.
I will begin my seminar with a pedagogical introduction to skyrmions and explain how these spin textures arise naturally in magnets with broken inversion symmetry and spin-orbit coupling. I will describe a variety of experiments emphasizing the unusual properties of skyrmions and their potential applications. In the second half of my talk, I will describe recent theoretical progress [1,2] on understanding the Hall and transverse thermoelectric responses observed in skyrmion phases involving both the momentum-space Berry curvature of the bands and the real-space Berry curvature of the textures.
 N. Verma, Z. Addison, M. Randeria; Science Advances 8, eabq2765 (2022)
 Z. Addison, L. Keyes, M. Randeria; arXiv:2303.01609
Short Bio: Mohit Randeria is a Professor of Physics at The Ohio State University. His research focuses on the theory of correlated and topological quantum materials. He obtained his BTech from IIT Delhi, MS from Caltech, and Ph.D. from Cornell. After a post-doc at the University of Illinois at Urbana-Champaign, he taught at Stony Brook, was on the staff of Argonne National Labs, and on the faculty of the Tata Institute of Fundamental Research, before coming to Ohio State in 2004. He has held visiting professorships at Berkeley, MIT, and Urbana-Champaign. He is a Fellow of the American Physical Society (APS) and the American Association for the Advancement of Science (AAAS). He was awarded the 2022 John Bardeen Prize for his work on superconductivity. More information about his research can be found at https://u.osu.edu/randeriagroup/
Host: Shulei Zhang