Band structure formation in magnonic Bragg gratings superlattice

The features of spin-wave propagation in a magnonic superlattice are investigated theoretically and experimentally. This superlattice consists of periodic metallic gratings, having two non-equal periods located at the surface of the ferromagnetic film. It is shown that two band gaps are formed in the spin-waves spectrum within the first Bragg zone. A theoretical model using a coupled waves model and equating magnetic permeabilities at the surface boundaries demonstrating the mechanism of band structure formation was developed. Experimental data obtained with microwave and Brillouin light scattering techniques are in good agreement with theoretical results.