Experimental verification of domain-wall tilting induced by Dzyaloshinskii Moriya interaction in current-driven domain-wall motion

Abstract

Current-driven domain-wall motion is inevitably accompanied by tilting of the domain wall. There are two possible tilting mechanisms proposed either by the Oersted field or by the Dzyaloshinskii Moriya interaction (DMI). Here, we present the experimental observation that the DMI-induced mechanism plays decisive role in the domain-wall tilting for various films. Despite of opposite signs of the DMI and spin–orbit torque, all films showed that the domain-wall tilting direction follows the domain-wall propagation direction as predicted by DMI-induced mechanism. The present observation therefore indicates that the DMI-induced mechanism—rather than the Oersted-field-induced mechanism—is dominant in the domain-wall tilting for practical films of efficient current-driven domain-wall motion.