Power and initial pulse width dependent soliton velocity in ferrite films

Abstract

Magnetostatic backward volume wave propagation in yttrium–iron–garnet thin films supports soliton formation and propagation, which is modeled by the nonlinear Schroedinger equation. Previous experimental data have shown that the propagation velocity depends both on the initial pulse power and the duration; however, in the nonlinear Schroedinger solution the soliton velocity, or wave number deviation, is a free parameter that is independent of the initial pulse characteristics. It is shown that these dependences on the initial pulse parameters arise simply from the nonlinear nature of the magnetostatic backward volume wave dispersion relation. Moreover, this same dependence is predicted in the nonlinear Schroedinger model, but the deviation in wave number is determined by the initial pulse characteristics and is no longer a free parameter.