Dipole-exchange propagating spin-wave modes in metallic ferromagnetic stripes

Results from Brillouin light scattering experiments on guided spin waves propagating along metallic magnetic stripes are presented and analyzed. The spin waves propagate along the stripe axis and form mode families due to geometrical confinement in the stripe geometry. In consequence, the allowed wave vectors are quantized in the transverse directions by stripe width and height. We show that each standing spin-wave resonance across the stripe width is associated with a particular guided mode. In the case of stripes magnetized along their length, the group velocity of the guided modes is negative and all modes have a volume character. When the stripes are magnetized along their width, the modes are characterized by a positive group velocity, and the spectrum consists of a series of volume and localized modes.