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Large-angle, gigahertz-rate random telegraph switching induced by spin-momentum transfer

Matthew R. Pufall·William H. Rippard·Shehzaad Kaka·Steven E. Russek·Thomas J. Silva·Jordan Katine·Matt Carey
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Abstract

We show that spin-polarized dc current passing through a small magnetic element induces two-state, random telegraph switching of the magnetization via the spin-momentum transfer effect. The resistances of the states differ by up to 50% of the change due to complete magnetization reversal. Fluctuations are seen for a wide range of currents and magnetic fields, with rates that can exceed 2 GHz, and involve collective motion of a large volume (10^4 nm^3) of spins. Switching rate trends with field and current indicate that increasing temperature alone cannot explain the dynamics. The rates approach a stochastic regime wherein dynamics are governed by both precessional motion and thermal perturbations.

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Matthew R. Pufall, William H. Rippard, Shehzaad Kaka, Steven E. Russek, Thomas J. Silva, Jordan Katine, Matt Carey. 2004-04-05. Large-angle, gigahertz-rate random telegraph switching induced by spin-momentum transfer. https://doi.org/10.1103/physrevb.69.214409

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