LAUSR

Radiation from a dynamic soliton is an issue of fundamental interest. Here, the authors study the emission from a domain wall in a ferromagnet taking into account the collective coordinate for the modulation of the wall thickness (breathing mode) in addition to the conventional coordinates, describing the sliding motion and the tilting angle of the wall plane. The breathing mode is shown to have a linear coupling to the fluctuation (spin wave), hence, it is the dominant source of spin-wave emission. The wave profile of the emitted spin wave is identified and the contribution to the Gilbert damping parameter due to the emission is estimated.