Current driven magnetization dynamics in ferromagnetic nanowires with Dzyaloshinskii-Moriya interaction

TL;DR

This paper investigates how Dzyaloshinskii-Moriya interaction influences current-driven magnetization dynamics in ferromagnetic nanowires, revealing the formation, stability, and motion of domain walls affected by DMI strength and sign.

Contribution

It provides an analytical model for domain wall width and dynamics in the presence of DMI, including the effects on threshold currents and drift velocities.

Findings

DMI induces spiral domain wall configurations.

A critical DMI value exists beyond which domain walls cannot form.

DMI reduces the minimum current needed to move domain walls.

Abstract

We study current induced magnetization dynamics in a long thin ferromagnetic wire with Dzyaloshinskii-Moriya interaction (DMI). We find a spiral domain wall configuration of the magnetization and obtain an analytical expression for the width of the domain wall as a function of the interaction strengths. Our findings show that above a certain value of DMI a domain wall configuration cannot exist in the wire. Below this value we determine the domain wall dynamics for small currents, and calculate the drift velocity of the domain wall along the wire. We show that the DMI suppresses the minimum value of current required to move the domain wall. Depending on its sign, the DMI increases or decreases the domain wall drift velocity.