Current-induced interactions of multiple domain walls in magnetic quantum wires

TL;DR

This paper demonstrates that charge currents in magnetic nanowires induce oscillatory interactions between domain walls, influencing their arrangements and enabling potential applications like tunable nano-mechanical oscillators.

Contribution

It introduces a novel mechanism for current-induced interactions between domain walls mediated by spin-dependent interference effects.

Findings

Interaction energy and torque oscillate with DW orientation and separation.

Current-induced DW interactions can be harnessed for nano-mechanical oscillators.

Impurities affect the strength and behavior of DW interactions.

Abstract

We show that an applied charge current in a magnetic nanowire containing domain walls (DWs) results in an interaction between DWs mediated by spin-dependent interferences of the scattered carriers. The energy and torque associated with this interaction show an oscillatory behaviour as a function of the mutual DWs orientations and separations, thus affecting the DWs' arrangements and shapes. Based on the derived DWs interaction energy and torque we calculate DW dynamics and uncover potential applications of interacting DWs as a tunable nano-mechanical oscillator. We also discuss the effect of impurities on the DW interaction.