Domain wall motion in Tb/Co multilayer wires with a large domain wall depinning field

Abstract

We have investigated domain wall (DW) motion in Tb/Co multilayer wires with a large DW depinning field ∼3.0 kOe and different wire widths. In this system, the DW depinning field was decreased as a linear dependence of injecting current. A high effective efficiency ε ∼ 5 × 10−13 T m2 A−1 was obtained. Threshold current density for the DW motion was found to be approximately 3 × 1011 A/m2 for the wires. High DW velocity up to 90 m/s was observed. In addition, the DW velocity showed a strong dependence on perpendicular (easy-axis) magnetic field. These results suggest that the Tb/Co wire is an excellent candidate for the high-speed and stability of stored information in DW-controlled devices.