The prospects of nonthermal magnetization switching in near-compensated rare earth iron garnets

Abstract

Ultrafast spin dynamics in a magnetically compensated rare earth iron garnet film driven by femtosecond optical pulses through the inverse Faraday effect is theoretically investigated. Numerical simulations based on the equations of motion for the Néel vector reveal the temporal evolution of the system and its trajectories in the effective potential landscape tuned by external field and temperature. The results demonstrate a clear threshold behavior: weak pulses induce only oscillations around the initial equilibrium state, while a stronger excitation results in a deterministic magnetization switching. The switching threshold is determined by the magnetic state of the sample on its phase diagramme as well as on the laser pulse helicity. This mechanism demonstrates a non-thermal and even non-absorptive pathway towards optomagnonic logic and memory devices.