Chaotic Dynamics of Spin Wave Instabilities

Abstract

Recently the investigation of spin wave phenomena has gained renewed interest due to observations of chaotic dynamics similar to those in other nonlinear physical systems such as turbulent fluids, lasers, plasmas and several solid state systems. The existence of low-frequency oscillations, self-pulsation and turbulence in microwave-pumped magnetic samples has been known since the early days of the spin wave parametric pumping experiments [1]. For years the origin of these self-oscillations was unclear, until several Soviet authors [2] showed that they resulted from the nonlinear dynamics of spin waves when pumped above the threshold for parametric excitation. However their extensive work fell short of connecting the spin wave turbulence phenomena with the modern ideas of chaotic dynamics of nonlinear dissipative systems.