2025/03/31 by Sayed Ali Akbar Ghorashi, Qiang Li, Ghorashi, Sayed Ali Akbar +1 · 9 citations
Physics and Astronomy · Materials Science · #Topological Materials and Phenomena #Magnetic properties of thin films #Chemical and Physical Properties of Materials
paper · doi:10.48550/arxiv.2504.00122
Altermagnets have been identified as the third category of magnetic materials, exhibiting momentum-dependent spin splitting characterized by even powers of momentum. In this study, we show that when subjected to elliptically polarized light, these materials serve as an exemplary framework for the dynamic generation of topological bands featuring higher-order spin-orbit coupling (SOC). Notably, while the generated Zeeman field remains invariant to the particular altermagnetic ordering, the induced higher-order SOCs are related to the magnitude and symmetry of the altermagnetic order. Specifically, we show that an altermagnet exhibiting kn-spin splitting can generate spin-orbit couplings up to kn-1. In the limit of circularly polarized light, the only correction is kn-1, with all lower-order contributions being nullified. Interestingly, light-induced SOCs significantly impact the low-energy band topology, where their Chern numbers change by ΔC =± 1,2,3 for d,g,f-wave altermagnets. Finally, we find a critical field in which a persistent spin texture is realized, a highly desirable state with predicted infinite spin lifetime. Our work showcases light as a powerful, controllable tool for engineering complex and exciting phenomena in altermagnets.