The role of spin orbit coupling in optically induced ultrafast magnetic dynamics

Spin–orbit coupling (SOC) plays a major role in solid-state magnetism. Its effects range from completely defining the splitting of f states in rare earths to the correct prediction of the ground-state orientation of the magnetic moment in transition metals. The breaking of symmetries that it produces is the main tool for addressing magneto-optical effects. In this paper we theoretically study the possibility of all-optical spin switching. By simulating the effect of an ultrashort laser pulse on an electronic system, we show the crucial role of SOC in the spin dynamics occurring in this regime. The role of other parameters is also analysed. Finally, we show the possibility of obtaining an all-optical spin switching in the subpicosecond time regime.