Ferrimagnetic Domain Wall Motion Induced by Damping-like Spin-orbit Torque

We theoretically and numerically investigate ferrimagnetic domain wall motion driven by damping-like spin-orbit torque. We find that the damping-like spin-orbit torque combined with the interfacial Dzyaloshinskii-Moriya interaction efficiently drives the ferrimagnetic domain wall especially at the angular momentum compensation point. We obtain the analytic expression of the domain wall velocity with respect to the current density and the net spin density, which is in agreement with numerical simulation. The analytic expression is applicable to arbitrary compensation conditions, ranging from the ferromagnetic limit to the antiferromagnetic limit, and is thus useful to design and interpret ferrimagnetic domain wall experiments at various temperatures or compositions.