Spin-wave localization between nearest and next-nearest neighboring holes in an antidot lattice

Broadband spectroscopy on spin waves is performed on a square Ni 80 Fe 20 antidot lattice with deep-submicron holes. Depending on the in-plane magnetic field H applied under different angles η , characteristic multiple resonances are resolved. Substantiated by dynamic micromagnetic simulations, these reflect different types of modes, i.e., extended and localized modes. Depending on η , modes are found to localize between nearest or next-nearest neighboring holes. In a small regime of η , they coexist.