CONTROLLING CHAOS IN FERROMAGNETIC-RESONANCE

The chaotic response of yttirum iron garnet (YIG) films in high-power ferromagnetic resonance (FMR) has been successfully controlled in experiments using a time-delayed control method. The ac component of the FMR signal was delayed and used to perturb a system parameter, the static magnetic field. The application of the perturbations initially modified the chaotic oscillations in the FMR absorption signal, converting them to periodic oscillations. Increasing the gain lead to a period halving (a debifurcation) of the controlled periodic oscillation, and with sufficient gain, all oscillations were eliminated and the quiescent state is achieved. Numerical simulations yielded good agreement with the experimental results.