A three-dimensional spin-diffusion model for micromagnetics

TL;DR

This paper introduces a finite-element computational model that simulates three-dimensional spin diffusion coupled with magnetization dynamics, applicable to magnetic multilayers and domain-wall motion, enhancing the understanding of spintronic phenomena.

Contribution

The paper presents a novel finite-element scheme that integrates spin diffusion with micromagnetic simulations, including models for spin torque and domain-wall motion, in a unified computational framework.

Findings

Successfully models spin accumulation in magnetic and nonmagnetic materials.

Capable of simulating time evolution or adiabatic approximation of spin dynamics.

Applicable to multilayer structures and domain-wall motion studies.

Abstract

We implement a finite-element scheme that solves the Landau-Lifshitz-Gilbert equation coupled to a diffusion equation accounting for spin-polarized currents. The latter solves for the spin accumulation not only in magnetic materials but also in nonmagnetic conductors. The presented method incorporates the model by Slonczewski for the description of spin torque in magnetic multilayers as well as the model of Zhang and Li for the description of current driven domain-wall motion. Furthermore it is able to do both resolve the time evolution of the spin accumulation or treat it in an adiabatic fashion by the choice of sufficiently large time steps.