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.
@article{arxiv.1209.4926,
title = {Spectral analysis of topological defects in an artificial spin-ice lattice},
author = {Sebastian Gliga and Attila Kákay and Riccardo Hertel and Olle Heinonen},
journal= {arXiv preprint arXiv:1209.4926},
year = {2013}
}