Magnetization reversal triggered by spin-polarized current in magnetic nanowires

It is shown experimentally that a pulsed current driven through a Ni nanowi re provokes an irreversible magnetization reversal at a field differing fro m the spontaneous switching field H-sw by DeltaH of as much as 40% of H-sw. The state of the magnetization is assessed by anisotropic magnetoresistanc e measurements carried out on single, isolated nanowires with and without s pin polarizer (Co/Cu multilayers). The parameter DeltaH is studied as a fun ction of the angle theta between the applied field and the wire. A shift of about 90 degrees between both profiles DeltaH (theta) with and without spi n polarizer shows that the observed effect is related to the spin polarizat ion of the current. The results are interpreted with a model of generalized Landau-Lifshitz-Gilbert equation with spin-polarized current.