A multi-scale approach for magnetisation dynamics: Unraveling exotic magnetic states of matter

TL;DR

This paper introduces a multi-scale simulation method for magnetisation dynamics that effectively models the interaction of magnetic skyrmions and domain walls with lattice defects, bridging atomistic and continuum descriptions.

Contribution

The paper presents a novel multi-scale approach that accurately captures defect effects on magnetic textures by coupling atomistic and continuum models seamlessly.

Findings

Simulated skyrmions interacting with lattice defects.

Uncovered new physical effects in magnetic systems.

Efficiently solves Landau-Lifshitz-Gilbert equations across scales.

Abstract

Crystallographic lattice defects strongly influence dynamical properties of magnetic materials at both microscopic and macroscopic length scales. A multi-scale approach to magnetisation dynamics, which is presented in this paper, accurately captures such effects. The method is illustrated using examples of systems with localized, non-trivial topological properties, e.g. in the form of skyrmions and chiral domain walls that interact with lattice dislocations. Technical aspects of the methodology involve multi-scale magnetisation dynamics that connects atomistic and continuum descriptions. The technique is capable of solving the Landau-Lifshitz-Gilbert equations efficiently in two regions of a magnetic material --- the mesoscopic and the atomistic regions, which are coupled in a seamless way. It is demonstrated that this methodology allows simulating realistically-sized magnetic skyrmions interacting with material defects and novel physical effects, uncovered using this theoretical methodology, are described.