Current induced domain wall motion

In this project we present CIDM transport measurements in nanowires with perpendicular anisotropy employing the extraordinary Hall effect (EHE). By making use of the distinct symmetries of the effects of the Oersted field, Joule heating and spin torque, their contributions to the DW depinning can be unambiguously extracted. This allows us to deduce the amplitude of the non-adiabaticity factor ß excluding Oersted field effects.

In addition to the spin torque, the injection of the current leads to an additional Oersted field concentric around the wire axis. The amplitude of this Oersted field can be large at the wire edges and may significantly affect the DW dynamics as well as the domain structure within the wire. In general, for the determination of the spin torque terms, the contribution of Oersted field to the DW displacement needs to be ascertained to separate the different contributions and this is still lacking for out-of-plane magnetized materials. The resulting force fom the Oersted field on a DW in thin in-plane magnetized materials is zero and therefore does not affect the DW displacement.