Host: Hanghui Chen, NYU Shanghai
Abstract:
Altermagnetism is characterized spin-orbit free compensated spin lattice connected by rotation instead of translation or inversion. Thus, the spin-degeneracy is lifted due to broken {T||t} or {T||i} symmetry. However, it can also be viewed as compensated spin order with wave vector q=0 but zero net moment. Thus, it possesses both features from antiferromagnetism and ferromagnetism. Based on first-principles calculations, we identified a pressure induced antiferromagnetism to altermagnetism transition in I4/m phase of ternary iron-selenide A2Fe4Se5. We found the induced altermagnetism may lead to exotic superconducting pairing symmetry. Furthermore, we propose a Hubbard-like “minimal model” for altermagnetism, and we show spin-triplet SC can be induced by dominating altermagnetic spin fluctuation.
Biography:
Chao Cao is a professor at the School of Physics, Zhejiang University. He obtained his Ph. D. from the University of Florida in 2008, where he also worked as postdoc for another year. Before he moved to Zhejiang University in 2022, he was professor of Physics in Hangzhou Normal University between 2010 and 2021. His research interests focus on first-principles study of strongly correlated materials and superconductivity. He was among the first to identify the electronic structure of iron-based and chromium-based superconductors. He has published approximately 100 papers with total citations of ~ 5600. He was the recipient of 2009 Nicholas Metropolis Award from APS.
Seminar by the NYU-ECNU Institute of Physics at NYU Shanghai