MOTION OF A MAGNETIC DOMAIN-WALL TRAVERSED BY FAST-RISING CURRENT PULSES

A Bloch wall is predicted to undergo finite displacements when traversed by a current pulse with short rise time less-than-or-equal-to 20 ns and long fall time, in thin films of metallic ferromagnets. In Ni-Fe films of thickness 85-150 nm, pulses with peak current density congruent-to 1 x 10(7) A/cm2 are expected to induce wall displacements of order 0.1-1-mu-m. This effect originates from the s-d exchange interaction. It is phenomenologically similar to the well-known "wall streaming" motion of Bloch walls subjected to fast-rising pulses of hard-axis magnetic field. The effect is related to the existence of a novel, current-induced, term in the expression for the momentum of a magnetic domain wall.