A New Branch of the Spectrum of Single Domain Wall Excitations in Magnetic Garnet Films

Abstract
180° and 90° domain walls in Bi-substituted [110] and [100] oriented garnet films with in-plane magnetization are studied by means of planar excitation-detection structures at microwave frequencies. New multiple resonance modes of single domain walls with very low linewidth (4.2 MHz) are observed at frequencies near 1 GHz. The resonances are excited by rf magnetic fields which are parallel or perpendicular to the wall plane. Resonance frequencies show a nonlinear dispersion dependence on the mode number. They decrease with an increasing static in-plane magnetic field normal to the wall plane. With decreasing film thickness the resonance frequencies increase. In addition the well known low-frequency resonances related to the wall translations or its flexural vibrations (Goldstone modes) are also observed in these samples.