Current-induced dynamics of a monodomain ferromagnet in an external magnetic field applied in easy magnetic plane: Macrospin model

Numerical results on current-induced magnetization dynamics of a ferromagnet are presented in the framework of a macrospin model. The Landau--Lifshitz--Gilbert equation is used to study the magnetic dynamics for an arbitrary angle between the magnetic field and injected spin-current polarization when they both lie in the easy magnetic plane. It is shown that in some configurations, the magnetic oscillations can reach a significant amplitude (observable via the giant magnetoresistance effect) and frequencies of dozens of gigahertz. Moreover, the model also predicts frequency jumps of the steady magnetization precession.