Time-domain studies of very-large-angle magnetization dynamics excited by spin transfer torques

被引：47

作者：

Krivorotov, I. N. ^{[1
]}

Emley, N. C. ^{[2
]}

Buhrman, R. A. ^{[2
]}

Ralph, D. C. ^{[2
]}

机构：

[1] Univ Calif Irvine, Dept Phys & Astron, Irvine, CA 92697 USA

[2] Cornell Univ, Ithaca, NY 14853 USA

来源：

PHYSICAL REVIEW B | 2008年 / 77卷 / 05期

关键词：

D O I：

10.1103/PhysRevB.77.054440

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We describe time-domain measurements which provide 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 steplike dependence on magnetic field, consistent with simulations which predict that the reversal trajectories differ by integer numbers of precession cycles. Storage-oscilloscope measurements of individual experimental traces reveal nonperiodic 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.

引用

页数：9

共 71 条

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