Discretization anisotropy in micromagnetic simulations

TL;DR

This paper investigates how finite difference discretization introduces anisotropy in micromagnetic simulations, affecting energy calculations, and proposes strategies to reduce this numerical artifact for more accurate modeling.

Contribution

It reveals the impact of discretization anisotropy in micromagnetic simulations and suggests methods to mitigate it by choosing proper stencils and smaller cells.

Findings

Discretization anisotropy can be comparable to physical energy scales.

Proper stencil selection reduces anisotropy effects.

Smaller discretization cells mitigate anisotropy.

Abstract

Finite difference based micromagnetic simulations are a powerful tool for the computational investigation of magnetic structures. In this paper, we demonstrate how the discretization of continuous micromagnetic equations introduces a numerical 'discretization anisotropy'. We demonstrate that, in certain scenarios, this anisotropy operates on an energy scale comparable to that of intrinsic physical phenomena. Furthermore, we illustrate that selecting appropriate finite difference stencils and minimizing the size of the discretization cells are effective strategies to mitigate discretization anisotropy.