Current-driven chaotic magnetization dynamics in microwave assisted switching of spin-valve elements

The switching process of a uniformly magnetized spin-valve is considered. The system is subject to external dc applied fields and injected radio-frequency (RF) spin-polarized currents. The possibility of using the RF power to obtain a reduced coercivity of the particle is related to the onset of chaotic magnetization dynamics for moderately low values of the RF current amplitude. Perturbation technique for the estimation of the reduced coercive field is developed and applied to the microwave assisted switching of the particle. Numerical simulations confirm the predictions of the theory. (C) 2011 American Institute of Physics. [doi:10.1063/1.3556701