Surface spin waves propagation in tapered magnetic stripe

We analytically investigate properties of magnetostatic surface spin wave propagation in irregular narrow ferromagnetic waveguides that are important elements of magnonic logic. The developed mathematical model is based on the Galerkin method. Theoretical investigations are proved by Brillouin light scattering spectroscopy. We demonstrate that the confinement effect in the narrow waveguide leads to multimode regime propagation, wave beats, and energy redistribution. These processes can be controlled by tuning the structure and excitation parameters. A gradual change in the waveguide width can be used to vary the spin wave energy density. Our results show that the impact of the width effect and the irregularity of the waveguide on the spin wave propagation are crucial. Published under license by AIP Publishing.