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

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.