Time-Domain Studies of Very-Large-Angle Magnetization Dynamics Excited by Spin Transfer Torques
arXiv:0709.0560 · doi:10.1103/PhysRevB.77.054440
Abstract
We describe time-domain measurements which provide new information about the large-angle nonlinear dynamics of nanomagnets excited by spin-transfer torque from a spin-polarized current. Sampling-oscilloscope measurements, which average over thousands of experimental time traces, show that the mean reversal time for spin-transfer-driven magnetic switching has a step-like dependence on magnetic field, because an integer number of precession cycles is required for reversal. Storage-oscilloscope measurements of individual experimental traces reveal non-periodic large-amplitude resistance variations at values of magnetic field and current in a crossover region between the regimes of spin-transfer-driven switching and steady-state precession. We also observe directly the existence of time-dependent switching, on the nanosecond scale, between different precessional modes and between a precessional mode and a static state, at particular values of magnetic field and current bias.
20 pages, 6 figures, submitted to Phys. Rev. B
References in corpus (5)
- Excitations of incoherent spin-waves due to spin-transfer torque
- Spin-torque switching: Fokker-Planck rate calculation
- Large-amplitude coherent spin waves exited by spin-polarized current in nanoscale spin valves
- Current-driven destabilization of both collinear configurations in asymmetric spin-valves
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Cited by in corpus (6)
- Spin Transfer Torques
- Experimental Test of Analytic Theory of Spin Torque Oscillator Dynamics
- Resonant Spin-Transfer-Driven Switching of Magnetic Devices Assisted by Microwave Current Pulses
- Biased quasi ballistic spin torque magnetization reversal
- Non-stationary magnetization dynamics driven by spin transfer torque
- Micromagnetic simulations of persistent oscillatory modes excited by spin-polarized current in nanoscale exchange-biased spin valves