Induced and parametric excitation of spin waves by a light field with a discrete spectrum and optically induced spin echo

Abstract

Induced and parametric excitation of spin waves by a light field and light-induced spin echo are considered. The static and steady-state dynamic magnetizations in the light field are determined, and the phase diagrams of the system in magnetic and light fields are constructed. The threshold of parametric excitation, the amplitude of stationary oscillations, and the trajectories described by the end point of the magnetic moment vector are calculated for the case of light-induced nonlinear ferromagnetic resonance. The trajectories can be topologically different. The transition between states with different trajectories occurs as a phase transition. The parameters of the light-induced spin echo are determined.