title: Spectral analysis of topological defects in an artificial spin-ice lattice.
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 quasistatic and equilibrium behavior of the spin-ice lattice. Here, we study the eigenmode dynamics of such defects in a square lattice consisting of stadiumlike 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 that can be measured experimentally.
authors.affiliation: Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, USA and Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Gliga
authors.affiliation: Peter Grünberg Institut (PGI-6), Forschungszentrum Jülich GmbH, D-52428 Jülich, Germany.
authors.forename: Attila
authors.initials: A
authors.lastname: Kákay
authors.affiliation: Institut de Physique et Chimie des Matériaux de Strasbourg, Université de Strasbourg, CNRS UMR 7504, 67034 Strasbourg, France.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Hertel
authors.affiliation: Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA and Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208, USA.
authors.forename: Olle G
authors.initials: OG
authors.lastname: Heinonen