Laser-induced controllable magnetic order switching and spin injection in altermagnets
Phys. Rev. B 114, 034425 – Published 31 July, 2026
DOI: https://doi.org/10.1103/wfn4-2gy6
Abstract
Altermagnets have zero net magnetization and nonrelativistic spin splitting, which is ideal for spintronic applications. The control of the spin state is of crucial importance. Here, the laser-induced spin dynamics in an altermagnet/metal heterostructure has been investigated using the real-time time-dependent density functional theory. The laser irradiation induces the unbalanced demagnetizations of the opposite-spin sublattices, resulting in an ultrafast magnetic order transition of the altermagnet. After irradiated by laser pulses with different fluences and polarizations, the altermagnet can transiently turn to ferrimagnetic, ferromagnetic, or nonmagnetic states. Simultaneously, the spins are injected into the nonmagnetic substrate with a negligible charge injection. Those phenomena are caused by the intersite electron transfers of both spin channels. As the two opposite-spin sublattices can be selectively excited according to the rotational symmetry of the altermagnet, the direction of the magnetization of the altermagnet and the injected spin component can be controlled by using different linearly polarized laser pulses. The research demonstrates the laser-induced controllable magnetic order switching and spin injection of the altermagnetic system, which paves the way for high-speed spintronic applications.
