Time-Domain Studies of Very-Large-Angle Magnetization Dynamics Excited by Spin Transfer Torques
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.
Cite
@article{arxiv.0709.0560,
title = {Time-Domain Studies of Very-Large-Angle Magnetization Dynamics Excited by Spin Transfer Torques},
author = {I. N. Krivorotov and N. C. Emley and R. A. Buhrman and D. C. Ralph},
journal= {arXiv preprint arXiv:0709.0560},
year = {2009}
}
Comments
20 pages, 6 figures, submitted to Phys. Rev. B