Formation of envelope solitons of spin-wave packets propagating in thin-film magnon crystals

The formation of light envelope solitons has been experimentally observed under the pulsed excitation and propagation of radio-frequency spin-wave packets in a magnon crystal, a periodic magnetic film structure. The magnon crystal has been fabricated from a thin single-crystal yttrium iron garnet (YIG) film. The envelope solitons have been excited at frequencies corresponding to the edges of the Bragg-resonance-induced band gaps of the spin-wave spectrum of the magnon crystal. A theoretical explanation of the observed phenomenon has been proposed with the use of the numerical simulation of the formation of solitons based on the nonlinear Schrödinger equation.