Abstract
We have studied field- and current-driven domain-wall (DW) creep motion in a perpendicularly magnetized multilayer wire by real-time Kerr microscopy. The application of a dc current of density of assisted only the DW creeping under field in the same direction as the electron flow, a signature of spin-transfer torque effects. We develop a model dealing with both bidirectional spin-transfer effects and Joule heating, with the same dynamical exponent for both field- and current-driven creep, and use it to quantify the spin-transfer efficiency as in our wires, confirming the significant nonadiabatic contribution to the spin torque.
- Received 13 September 2009
DOI:https://doi.org/10.1103/PhysRevLett.104.137205
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