Crystal Symmetry Selected Pure Spin Photocurrent in Altermagnetic Insulators

作     者：Dong, Ruizhi Cao, Ranquan Tan, Dian Fei, Ruixiang 

作者机构：School of Physics Beijing Institute of Technology Beijing100081 China Key Lab of Advanced Optoelectronic Quantum Architecture and Measurement Ministry of Education Beijing Institute of Technology Beijing100081 China Shenzhen Institute for Quantum Science and Engineering Department of Physics Southern University of Science and Technology Shenzhen518055 China 

出 版 物：《arXiv》 (arXiv)

年 卷 期：2024年

核心收录：

主　　题：Crystal symmetry 

摘      要：The generation of time-reversal-odd spin-current in metallic altermagnets has attracted considerable interest in spintronics. However, producing pure spin-current in insulating materials remains both challenging and desirable, as insulating states are frequently found in antiferromagnets. Nonlinear photogalvanic effects offer a promising method for generating spin-current in insulators. We here revealed that spin and charge photocurrents in altermagnets are protected by spin point group symmetry. Unlike the photocurrents in parity-time symmetric materials, where spin-orbit coupling (SOC) induces a significant charge current, the spin-current in altermagnets can exist as a pure spin current along specific crystal directions regardless of SOC. We applied our predictions using first-principles calculations to several distinct materials, including wurtzite MnTe and multiferroic BiFeO3. Additionally, we elucidated the previously overlooked linear-inject-current mechanism in BiFeO3 induced by SOC, which may account for the enhanced bulk photovotaic effect in multiferroics. © 2024, CC BY.