Spectral analysis of topological defects in an artificial spin-ice lattice

TL;DR

This paper uses micromagnetic simulations to analyze the spectral signatures of topological defects like monopoles and strings in artificial spin-ice lattices, aiding experimental detection and understanding of their dynamics.

Contribution

It introduces a spectral analysis method to identify and distinguish topological defects in artificial spin-ice structures through their eigenmode signatures.

Findings

Topological defects show unique spectral signatures.

Eigenmode analysis can distinguish monopoles from strings.

Results facilitate experimental detection of defects.

Abstract

Arrays of suitably patterned and arranged magnetic elements may display artificial spin-ice structures with topological defects in the magnetization, such as Dirac monopoles and Dirac strings. It is known that these defects strongly influence the quasi-static and equilibrium behavior of the spin-ice lattice. Here we study the eigenmode dynamics of such defects in a square lattice consisting of stadium-like thin film elements using micromagnetic simulations. We find that the topological defects display distinct signatures in the mode spectrum, providing a means to qualitatively and quantitatively analyze monopoles and strings which can be measured experimentally.