Current-induced domain wall motion driven by spin–orbit torque and Dzyaloshinskii–Moriya interaction in Pt/GdFeCo and Rh/GdFeCo wires

Abstract

We investigated current-induced domain wall motion (CIDWM) driven by spin–orbit torque and Dzyaloshinskii–Moriya interaction (DMI) in ferrimagnetic Pt/GdFeCo/SiN and Rh/GdFeCo/SiN wires with perpendicular magnetic anisotropy at room temperature. We found that CIDWM in the Pt/GdFeCo wire exhibits nearly two times smaller in critical current density and about four times larger in DW mobility compared to the Rh/GdFeCo wire. By measuring the CIDWM under a longitudinal in-plane magnetic field, the DMI constant (D) was estimated for both wires. The estimated value of D for the Pt/GdFeCo wire is approximately seven times larger than the Rh/GdFeCo wire. It indicated that the Pt/GdFeCo wire revealed the CIDWM with much higher efficiency, mainly attributed to the much larger DMI, which may come from significantly stronger interfacial heavy metal/ferrimagnet hybridization in the Pt/GdFeCo wire.