Minimization of Ohmic losses for domain wall motion in a ferromagnetic nanowire

TL;DR

This paper proposes a resonant current method to efficiently move domain walls in ferromagnetic nanowires, significantly reducing Ohmic losses and enabling higher speeds without damaging the wire.

Contribution

It introduces a resonant, time-dependent current approach to minimize Ohmic losses in domain wall motion, optimizing wire parameters for maximum efficiency.

Findings

Resonant current reduces Ohmic losses significantly.

Optimal parameters depend on domain wall velocity.

Below a critical velocity, dc current minimizes losses.

Abstract

We study current-induced domain-wall motion in a narrow ferromagnetic wire. We propose a way to move domain walls with a resonant time-dependent current which dramatically decreases the Ohmic losses in the wire and allows to drive the domain wall with higher speed without burning the wire. For any domain wall velocity we find the time-dependence of the current needed to minimize the Ohmic losses. Below a critical domain-wall velocity specified by the parameters of the wire the minimal Ohmic losses are achieved by dc current. Furthermore, we identify the wire parameters for which the losses reduction from its dc value is the most dramatic.