Heavy and Light Monopoles in Magnetic Reversion in Artificial Spin Ice

TL;DR

This theoretical study explores the dynamics of magnetic monopoles in artificial spin ice, revealing two distinct reversion mechanisms involving either stationary or mobile monopoles and the formation of Dirac chains.

Contribution

It introduces a theoretical model analyzing how nanoisland parameters influence magnetic reversion mechanisms and emergent monopole excitations in artificial spin ice systems.

Findings

Two reversion mechanisms with different monopole behaviors identified

Heavy monopoles are stationary and do not form Dirac chains

Light monopoles are mobile and generate extensive Dirac chains

Abstract

This work makes a theoretical study of the dynamics of emergent elemental excitations in artificial spin ice systems with hexagonal geometry during the magnetic reversion of the system. The magnetic and physical parameters of the nanoislands that form the array are considered as variables in the study. The parameters considered are: the energy barrier for the inversion of each nanoisland, the magnetic moment of the nanomagnets and the possible disorder in the sample. Our results show that the reversion dynamic presents two distinct mechanisms of magnetic reversion, with different elemental excitations for each mechanism. The first mechanism presents a reversion with the appearance of magnetic monopoles that do not move in the samples (heavy monopoles) and the absence of Dirac chains. In the other mechanism elemental magnetic excitations (light monopoles) appear that move great distances in the sample, giving rise to extensive Dirac chains during the magnetic reversion.