Stochastic ferrimagnetic Landau-Lifshitz-Bloch equation for finite magnetic structures

Abstract

After deriving the stochastic version of the Landau-Lifshitz-Bloch equation for disordered ferromagnets, the authors develop a computationally efficient coarse-grained model for ferrimagnets with a finite size. This model is shown to be accurate for applied heat pulses of down to ten picoseconds. Although the authors observe switching with a ferromagneticlike state for a 50-fs pulse, no deterministic switching is obtained. This leads to the conclusion that the two-spin model is probably not capable of describing deterministic all-optical switching at all.