Reversal of Domain Wall Motion in Perpendicularly Magnetized TbFeCo-Based Wires: Size Dependence

Abstract

Current-induced domain wall (DW) motion has been investigated in interfacial asymmetric SiO 2 /TbFeCo/Pt wires with different wire widths and thicknesses. The reversed DW motion was observed in these interfacial asymmetric wires at zero field and room temperature. This reversal of DW motion was attributed to the structural inversion asymmetry-induced spin–orbit torques (SOTs) from the Pt/TbFeCo interface and Pt layer of the wire. We found that the reversed DW velocity strongly depends on the size of wires, typically large for thin and narrow wires, suggesting that the SOTs effectively enhance the reversed DW velocity in these asymmetric TbFeCo wires.