Nonlinear Optomagnetic Signature of -Wave Altermagnets
Phys. Rev. Lett. 136, 226702 – Published 3 June, 2026
DOI: https://doi.org/10.1103/gly7-jzfl
Abstract
Altermagnetism, a recently discovered collinear magnetic order with net zero magnetization but exhibiting spin-splitting band structure, has attracted much research interest due to the rich fundamental physics and possible applications. In this Letter, we investigate the optomagnetic response of -wave altermagnets, focusing on the inverse Cotton-Mouton effect—the induction of static magnetization via linearly polarized light. We find that the direction of the induced magnetization is determined by the Néel vector. Moreover, its magnitude exhibits a periodic dependence on the polarization angle of the incident light, a hallmark of the system’s symmetry. Our findings demonstrate that the inverse Cotton-Mouton effect offers a direct method both for detecting -wave altermagnets and for probing their intrinsic properties.