Beyond ferromagnetic resonance: The inertial regime of the magnetization

An inertial regime of the magnetization dynamics at short time scales has been recently predicted for uniform magnetization. We study numerically the corresponding generalized Gilbert equation in both the time domain and in the frequency domain. The time dependence shows a typical nutation behavior that is superimposed to the usual precession of the magnetization around the static magnetic field. In the frequency domain, a second inertial resonance peak at high frequency-added to the usual ferromagnetic Resonance-takes place in the vicinity of the nutation frequency. The typical properties of the inertial resonance are investigated.