Auto-Oscillations and Chaos for Microwave Signals in Ferrite Single Crystals

Abstract
The recent progress of nonlinear dynamics has stimulated a renaissance of high-power ferromagnetic resonance experiments on ferrites, both under the aspects of basic research and application. We report on resonance experiments in yttrium iron garnet spheres probing chaotic scenarios above the first-order Suhl threshold. Different techniques have been proposed to change the observed irregular auto-oscillations of magnetization into regular motion. The delayed feedback control method of Pyragas is studied both in theory and experimental application.