Nonlinear Resonant and Chaotic Dynamics in Microwave Assisted Magnetization Switching

The switching process of a uniformly magnetized magnetic nanoparticle is considered. The particle is subject to applied fields having both dc and linearly-polarized radio-frequency (RF) components. 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 field amplitude. Perturbation technique for the evaluation 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.