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 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.
@article{arxiv.1310.5586,
title = {Ultrafast magnetization switching by spin-orbit torques},
author = {Kevin Garello and Can Onur Avci and Ioan Mihai Miron and Manuel Baumgartner and Abhijit Ghosh and Stéphane Auffret and Olivier Boulle and Gilles Gaudin and Pietro Gambardella},
journal= {arXiv preprint arXiv:1310.5586},
year = {2014}
}