This paper shows that the presence of two dynamical regimes, characterized by different precessional axes, is the origin of the nonmonotonic behavior of the output integrated power for large-amplitude magnetization precession driven by spin-polarized current in nanoscale exchange-biased spin valves. In particular, an abrupt loss in the integrated output power exists at the transition current between those two regimes. After the introduction of a time-frequency analysis of magnetization dynamics based on the wavelet transform, we performed a numerical experiment by means of micromagnetic simulations. Our results predicted that, together with a modulation of the frequency of the main excited mode of the magnetization precession, at high nonlinear dynamical regime the instantaneous output power of the spin-torque oscillator can disappear and then reappear at nanosecond scale.
|Titolo:||Nonstationary magnetization dynamics driven by spin transfer torque|
|Data di pubblicazione:||2009|
|Citazione:||Nonstationary magnetization dynamics driven by spin transfer torque / SIRACUSANO G; FINOCCHIO G; LA CORTE A; CONSOLO G; TORRES L; AZZERBONI B. - In: PHYSICAL REVIEW. B, CONDENSED MATTER AND MATERIALS PHYSICS. - ISSN 1098-0121. - 79:10(2009), pp. 104438.104438-104438.104441.|
|Appare nelle tipologie:||1.1 Articolo in rivista|