Breathing vibrations of a Néel wall

Abstract

One may sometimes regard a 180° Néel wall in a cubic ferromagnet as composed of two 90° subwalls or solitons. A spectrum of field-dependent natural frequencies for symmetric breathing of the subwall pair is derived from the Landau-Lifshitz equations in the limit of large uniaxial growth anisotropy and small spontaneous magnetization. The possibility of their excitation in the absence or presence of a Bloch line is discussed. Application to a garnet film of known characteristics predicts externally excitable modes with resonant frequencies near 2 GHz.