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

TL;DR

This paper theoretically explores ultrafast, non-thermal magnetization switching in rare earth iron garnets driven by femtosecond optical pulses, revealing threshold behavior and potential for optomagnonic devices.

Contribution

It introduces a theoretical model showing how femtosecond pulses can induce deterministic magnetization switching in near-compensated garnets, highlighting a non-thermal pathway.

Findings

Weak pulses cause oscillations without switching

Stronger pulses lead to deterministic magnetization reversal

Switching depends on external field, temperature, and pulse helicity

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 N\'eel 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.