Micromagnetic simulations of magnetization reversal in kagome artificial spin ice

Abstract

This work reports micromagnetic simulations used to study magnetization reversal in kagome artificial spin ice, taking into account the actual edge imperfections presented by the magnetic nanoislands as a source of disorder. An important advantage of the micromagnetic approach is to discretize a magnetic element in nanometric domains, allowing access to the sample magnetic moments distribution in detail. The limit case of zero disorder is accessed considering a system composed of perfect magnetic islands. The main result is the prediction of a critical angle between the applied magnetic field and the direction of one of the sublattices, above which Dirac strings emerge. For lower values, the reversal occurs through a bidimensional fashion, being smooth or abrupt depending on whether or not roughness is present, respectively. Finally, our simulations open the question of how the contour imperfections really influence the magnetic response of artificial spin ice.