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 eta, characteristic multiple resonances are resolved. Substantiated by dynamic micromagnetic simulations, these reflect different types of modes, i.e., extended and localized modes. Depending on eta, modes are found to localize between nearest or next-nearest neighboring holes. In a small regime of eta, they coexist. (C) 2008 American Institute of Physics.