Spin-orbit torques induced by spin Hall and interfacial effects in heavy metal/ferromagnetic bilayers allow for a switching geometry based on in-plane current injection. Using this geometry, we demonstrate deterministic magnetization reversal by current pulses ranging from 180 ps to ms in Pt/Co/AlOx dots with lateral dimensions of 90 nm. We characterize the switching probability and critical current Ic as a function of pulse length, amplitude, and external field. Our data evidence two distinct regimes: a short-time intrinsic regime, where Ic scales linearly with the inverse of the pulse length, and a long-time thermally assisted regime, where Ic varies weakly. Both regimes are consistent with magnetization reversal proceeding by nucleation and fast propagation of domains. We find that Ic is a factor 3–4 smaller compared to a single domain model and that the incubation time is negligibly small, which is a hallmark feature of spin-orbit torques.
Ultrafast magnetization switching by spin-orbit torques
Kevin Garello, Can Onur Avci, Ioan Mihai Miron, Manuel Baumgartner, Abhijit Ghosh, Stéphane Auffret, Olivier Boulle, Gilles Gaudin, Pietro Gambardella; Ultrafast magnetization switching by spin-orbit torques. Appl. Phys. Lett. 24 November 2014; 105 (21): 212402. https://doi.org/10.1063/1.4902443
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