Nonlinear self-localized dipole-exchange surface spin waves on ferromagnetic media.

Abstract

A type of self-localized, surface, dipole-exchange spin wave on a ferromagnet is predicted, the existence of which is controlled entirely by the nonlinear properties of the ferromagnetic medium. Dispersion equations have been obtained for dipole-exchange nonlinear spin waves and the influence of second-harmonic generation on the wave, propagating at the fundamental frequency, is investigated. The nonlinear Schr\"odinger equation, for the spin-wave envelope amplitude, is derived and its solitonic solutions are discussed. Estimates of the threshold values of the wave numbers of the propagating waves are obtained.