Power spectra of chaotic states in driven magnets

Abstract

Based on the symmetric two-mode model for driven ferro- and antiferromagnets, the authors study the power spectra of periodic and chaotic attractors of driven modes. Near the onset of a chaotic behaviour, they examine a scaling property and find the scaling constant beta ⁽²⁾ given by 10 log 2 beta ⁽²⁾ approximately=13.2. A strong sensitivity of the intensity and position of the fundamental spectral peak to the interactions between driven modes is demonstrated, which is consistent with the observed sensitivity of the auto-oscillation in magnetisation to the crystallographic anisotropy in YIG. The anomalous widespread spectrum of driven modes pointed out by Gottlieb and Suhl (1962) and recently by Anderson (1981) is partly attributed to a magnified broad spectrum of the developed strange attractor.