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Direct-Current Induced Dynamics in Co90Fe10/Ni80Fe20 Point Contacts

W. H. Rippard·M. R. Pufall·S. Kaka·S. E. Russek·T. J. Silva
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Abstract

We have directly measured coherent high-frequency magnetization dynamics in ferromagnet films induced by a spin-polarized DC current. The precession frequency can be tuned over a range of several gigahertz, by varying the applied current. The frequencies of excitation also vary with applied field, resulting in a microwave oscillator that can be tuned from below 5 GHz to above 40 GHz. This novel method of inducing high-frequency dynamics yields oscillations having quality factors from 200 to 800. We compare our results with those from single-domain simulations of current-induced dynamics.

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W. H. Rippard, M. R. Pufall, S. Kaka, S. E. Russek, T. J. Silva. 2003-09-01. Direct-Current Induced Dynamics in Co90Fe10/Ni80Fe20 Point Contacts. https://doi.org/10.1103/physrevlett.92.027201

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