Ultrafast Laser-Induced Spin Dynamics in All-Semiconductor Ferromagnetic CrSBr–Phosphorene Heterostructures

Ultrashort laser pulses are extensively used for efficient manipulation of interfacial spin injection in two-dimensional van der Waals (vdW) heterostructures. However, physical processes accompanying the photoinduced spin transfer dynamics on the all-semiconductor ferromagnetic vdW heterostructure remain largely unexplored. Here, we present a computational investigation of the femtosecond laser pulse induced purely electron-mediated spin transfer dynamics at a time scale of less than 50 fs in a vdW heterostructure. The latter is composed of two semiconducting monolayers, namely, a ferromagnetic material CrSBr and a nonmagnetic phosphorene, and is denoted as CrSBr-P. We observe an ultrafast spin injection from the Cr atoms to the P atoms in a few femtoseconds by both optically induced and interfacial atom-mediated spin transfer effects. We also show that the demagnetization and spin transfer in the ferromagnetic–nonmagnetic CrSBr-P vdW heterostructure can be sensitively manipulated by laser pulses with different fluences. Our study offers a microscopic understanding of spin dynamics in these vdW heterostructures aiming toward their potential spintronic applications, which rely on optically controlled spin transfer processes.