Simulating altermagnets using mumax+

TL;DR

This paper introduces a new simulation capability for altermagnets in mumax+, demonstrating analytical solution reproduction, magnon dispersion analysis, and skyrmion dynamics.

Contribution

It extends mumax+ to simulate altermagnets with a new magnet class, enabling advanced studies of their magnetic properties.

Findings

Reproduced analytical solutions for Nél domain walls.

Simulated magnon dispersion relations in altermagnets.

Studied Nél skyrmion motion under spin transfer torque.

Abstract

In this paper, we demonstrate how altermagnets can be simulated in the recently released micromagnetic simulation package mumax+. We have added a new magnet class for d-wave altermagnets and demonstrate how mumax+ is able to reproduce the analytical solutions for line profiles of the N\'eel vector and net magnetization for a Bloch domain wall. Next, we show simulation results of the magnon dispersion relation and its dependence on the anisotropic nature of the exchange interaction. Finally, we study the motion of a N\'eel skyrmion by applying a spin transfer torque. This new feature was implemented by extending the pre-existing code base for antiferromagnetic simulations. The object-oriented design of mumax+ allows for a correct calculation of the magnetostatic field in multi-sublattice systems, a feature that many other micromagnetic simulators lack.