Dynamics of topological defects in a two-dimensional magnetic domain stripe pattern

TL;DR

This paper develops a continuum model to describe how topological defects influence the evolution of magnetic domain patterns in two-dimensional films, validated by experiments showing the defect population's impact on magnetic susceptibility.

Contribution

It introduces a dynamical model linking topological defect populations to magnetic susceptibility changes in stripe patterns, aiding understanding of pattern melting transitions.

Findings

Model accurately predicts susceptibility changes due to defect dynamics

Experimental data confirms the defect population's role in pattern evolution

Susceptibility serves as a probe for defect dynamics and phase transitions

Abstract

Two dimensional magnetic films with perpendicular magnetization spontaneously form magnetic domain patterns that evolve or undergo symmetry transformations as a function of temperature. When the system is driven from equilibrium by a rapid change in temperature, topological pattern defects are the elementary pattern excitations that affect this evolution. An elastic continuum model is adapted to describe how a metastable population of topological defects alters the domain density and the magnetic susceptibility of the "stripe" magnetic domain pattern. Temporal changes in the susceptibility are interpreted using a dynamical equation describing the defect population. Recent experiments provide a quantitative verification of the model, and illustrate the use of the magnetic susceptibility to follow the population dynamics of topological defects in this system, and its potential role in investigating a pattern melting phase transition.