Magnetic switching dynamics in a ferrimagnetic two sub-lattice model including ultrafast exchange scattering

TL;DR

This study models heat-induced magnetization dynamics in a ferrimagnetic alloy, revealing conditions for transient ferromagnetic-like states and magnetization switching influenced by exchange scattering and equilibrium properties.

Contribution

Introduces a ferrimagnetic two-sublattice model including ultrafast exchange scattering to analyze heat-induced magnetization switching.

Findings

Transient ferromagnetic-like state can be achieved with strong excitation

Magnetization switching occurs only near the compensation point

Exchange scattering influences the dynamics significantly

Abstract

We study the heat-induced magnetization dynamics in a toy model of a ferrimagnetic alloy, which includes localized spins antiferromagnetically coupled to an itinerant carrier system with a Stoner gap. We determine the one-particle spin-density matrix including exchange scattering between localized and itinerant bands as well as scattering with phonons. While a transient ferromagnetic-like state can always be achieved by a sufficiently strong excitation, this transient ferromagnetic-like state only leads to magnetization switching for model parameters that also yield a compensation point in the equilibrium M(T) curve.