Influence of dipolar interaction on vortex dynamics in arrays of ferromagnetic disks.

The influence of the magnetostatic interaction on vortex dynamics in arrays of ferromagnetic disks is investigated by means of a broadband ferromagnetic-resonance setup. Transmission spectra reveal a strong dependence of the resonance frequency of vortex-core motion on the ratio between the center-to-center distance and the element size. For a decreasing ratio, a considerable broadening of the absorption peak is observed following an inverse sixth power law. An analogy between the vortex system and rotating dipoles is confirmed by micromagnetic simulations.