Saturation of magnetic films with spin-polarized current in presence of magnetic field

Influence of perpendicular magnetic field on the process of transversal saturation of ferromagnetic films with spin-polarized current is studied theoretically. It is shown that the saturation current $J_s$ is decreased (increased) in case of codirected (oppositely directed) magnetic field and current. There exists a critical current $J_c>J_s$ which provides “rigid” saturation – the saturated state is stable with respect to the transverse magnetic field of any amplitude and direction. Influence of the magnetic field on the vortex-antivortex crystals, which appear in pre-saturated regime, is studied numerically. All analytical results are verified using micromagnetic simulations.