High domain wall velocities induced by current in ultrathin Pt/Co/AlOx wires with perpendicular magnetic anisotropy

TL;DR

This study demonstrates high domain wall velocities in ultrathin Pt/Co/AlOx wires induced by current, with direct observation of displacement controlled by current parameters, revealing creep behavior at low currents and high velocities at higher currents.

Contribution

It provides direct experimental evidence of current-induced domain wall motion in ultrathin wires with perpendicular magnetic anisotropy, including velocity measurements up to 130 m/s.

Findings

Domain walls move under current pulses with velocities up to 130 m/s.

At low current densities, DW motion follows a creep law.

High velocities are achieved at higher current densities.

Abstract

Current-induced domain wall (DW) displacements in an array of ultrathin Pt/Co/AlOx wires with perpendicular magnetic anisotropy have been directly observed by wide field Kerr microscopy. DWs in all wires in the array were driven simultaneously and their displacement on the micrometer-scale was controlled by the current pulse amplitude and duration. At the lower current densities where DW displacements were observed (j less than or equal to 1.5 x 10^12 A/m^2), the DW motion obeys a creep law. At higher current density (j = 1.8 x 10^12 A/m^2), zero-field average DW velocities up to 130 +/- 10 m/s were recorded.