Thermally Assisted Current-Driven Bistable Precessional Regimes in Asymmetric Spin Valves

Abstract

Spin-transfer torque in asymmetric spin valves can destabilize both parallel and antiparallel configurations and can lead to precessional modes also in the absence of an external magnetic field. We find a bistable precessional regime in such systems and show that thermal fluctuations can excite transitions (telegraph noise) between the corresponding oscillatory regimes that are well separated by irreversible paths at low temperatures. Because of the thermally induced transitions, the frequency of the resulting current-driven oscillations is different from that obtained at very low temperatures. We also show that the power spectrum in the bistable region is dominated by the out-of-plane oscillatory mode.

4 pages, 3 figures

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Cited by in corpus (6)

• Lineshape distortion in a nonlinear auto-oscillator near generation threshold: Application to spin-torque nano-oscillators
• Stochastic resonance of a nanomagnet excited by spin transfer torque
• Field- and damping-like spin-transfer torque in magnetic multilayers
• Correlation of the angular dependence of spin-transfer torque and giant magnetoresistance in the limit of diffusive transport in spin valves
• Current-pulse-induced magnetic switching in standard and nonstandard spin-valves
• Computational study of microwave oscillations in absence of external field in nonstandard spin valves in the diffusive transport limit