Magnetization dynamics driven by the combined action of ac magnetic field and dc spin-polarized current

The spin-polarized current flowing through a ferromagnet can apply a torque able to drive magnetization reversal or to excite persistent dynamical states of magnetization. In the present work we simulate the dynamic behavior of nanomagnets in nanopillar spin valve structures due to the combined action of ac magnetic fields and dc spin-polarized current. The simulations are performed using a micromagnetic model which includes the effect of the spin-polarized current. We also discuss possible experimental realizations of the ac-field-assisted current-induced switching. Two particular cases of the ac-field polarization are studied: circular and linear. We find that in both cases ac field accelerates the switching process.