1. Current pulse induced toggle switching of dual-vortex magnetization in Ni80Fe20/Cu/Co nanopillar element.
- Author
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Kolthammer, J., Gardner, R., Speliotis, Th., Hong, Y. K., Abo, G., Liu, Q., and Choi, B. C.
- Subjects
SPIN transfer torque ,MAGNETIZATION ,FERROMAGNETISM ,NICKEL compounds ,IRON compounds - Abstract
The combined effect of the spin-transfer torque and circular Amperian field to the switching of the chiralities of the dual-vortex magnetization in multilayered Ni80Fe20/Cu/Co nanopillar elements (o\ = 100 nm) is investigated numerically. It is demonstrated that, by passing a current pulse through the nanopillar, the chirality of the Ni80Fe20 layer can be controllably switched while that of the fixed Co layer persists. Consequently, reliable toggle switching between bistable low- and high-MR states can be achieved by applying current pulses with appropriate amplitude, polarity, and duration. It is found that the magnetization dynamics after the onset of a current pulse includes the excitation of spin-wave eigenmodes and that the predominant process throughout is the precessional motion of the free-layer magnetization. A shift of the eigenfrequency is observed when the chirality of the free-layer vortex magnetization switches from parallel to antiparallel relative to that of the fixed layer. This frequency shift is attributed to dynamic magnetostatic coupling between the vortices. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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