Brillouin light scattering from quantized spin waves in micron-size magnetic wires

Abstract

An experimental study of spin-wave quantization in arrays of micron-size magnetic ${\mathrm{Ni}}_{80}{\mathrm{Fe}}_{20}$ wires by means of Brillouin light-scattering spectroscopy is reported. Dipolar-dominated Damon-Eshbach spin-wave modes laterally quantized in a single wire with quantized wave vector values determined by the width of the wire are studied. The frequency splitting between quantized modes, which decreases with increasing mode number, depends on the wire sizes and is up to 1.5 GHz. The transferred wave vector interval, where each mode is observed, is calculated using a light-scattering theory for confined geometries. The frequencies of the modes are calculated, taking into account finite-size effects. The results of the calculations are in a good agreement with the experimental data.