Non-stationary magnetization dynamics driven by spin transfer torque

Abstract

This paper shows that the presence of two dynamical regimes, characterized by different precessional-axis, is the origin of the non-monotonic behavior of the output integrated power for large-amplitude magnetization precession driven by spin-polarized current in nanoscale exchange biased spin-valves. In particular, at the transition current between those two regimes exists an abruptly loss in the integrated output power. 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 non-linear dynamical regime the instantaneous output power of the spin-torque oscillator can disappear and then reappear at nanosecond scale.

10 pages 4 figures, to be appear in Physical Review B

References in corpus (11)

• Microwave Oscillations of a Nanomagnet Driven by a Spin-Polarized Current
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• Magnetoresistance and spin-transfer torque in magnetic tunnel junctions
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• Large-angle, gigahertz-rate random telegraph switching induced by spin-momentum transfer
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• Stochastic theory of spin-transfer oscillator linewidths
• Micromagnetic simulations of persistent oscillatory modes excited by spin-polarized current in nanoscale exchange-biased spin valves

Cited by in corpus (7)

• Experimental evidence of self-localized and propagating spin wave modes in obliquely magnetized current-driven nanocontacts
• Micromagnetic understanding of the skyrmion Hall angle current dependence in perpendicular magnetized ferromagnets
• Time domain study of frequency-power correlation in spin-torque oscillators
• Non-Adlerian phase slip and non stationary synchronization of spin-torque oscillators to a microwave source
• Intrinsic synchronization of an array of spin-torque oscillators driven by the spin-Hall effect
• Domain wall dynamics driven by a localized injection of a spin-polarized current
• Micro-focused Brillouin light scattering study of the magnetization dynamics driven by Spin Hall effect in a transversely magnetized NiFe nanowire