Transition in mechanism for current-driven magnetic domain wall dynamics

We report a systematic study of the DW motion in perpendicularly magnetized Co/Ni nanowires having different thicknesses with structure inversion asymmetry. The transition from bulk to interfacial effects is confirmed as a change in the DW motion direction at a reduced layer thickness. The bias field dependence reveals that the adiabatic spin transfer torque (STT) dominates the DW motion in the thick regime, whereas the interfacial torque originating from the spin Hall effect (SHE) is responsible for the DW motion with a fixed DW chirality induced by the Dzyaloshinskii-Moriya interaction (DMI) in the thin regime. (C) 2014 The Japan Society of Applied Physics