We analyse the effect of the applied field (Happl) on the current-driven magnetization reversal in pillar-shaped Co/Cu/Co trilayers, where we observe two different types of transition between the parallel (P) and antiparallel (AP) magnetic configurations of the Co layers. If Happl is weaker than a rather small threshold value, the transitions between P and AP are irreversible and relatively sharp. For Happl exceding the threshold value, the same transitions are progressive and reversible. We show that the criteria for the stability of the P and AP states and the experimentally observed behavior can be precisely accounted for by introducing the current-induced torque of the spin transfer models in a Landau-Lifschitz-Gilbert equation. This approach also provides a good description for the field dependence of the critical currents.
Cite
@article{arxiv.cond-mat/0211371,
title = {Field dependence of magnetization reversal by spin transfer},
author = {J. Grollier and V. Cros and H. Jaffres and A. Hamzic and J. M. George and G. Faini and J. Ben Youssef and H. Legall and A. Fert},
journal= {arXiv preprint arXiv:cond-mat/0211371},
year = {2009}
}