Magnetic domain wall dynamics in the precessional regime: influence of the Dzyaloshinskii-Moriya interaction

TL;DR

This study investigates how the Dzyaloshinskii-Moriya interaction influences the dynamics of magnetic domain walls driven by out-of-plane magnetic fields, revealing relationships between DMI strength and domain wall velocity behaviors.

Contribution

It introduces a combined experimental and modeling approach to analyze domain wall velocities in systems with varying DMI, especially when DMI and demagnetizing fields are comparable.

Findings

Walker velocity relates to DMI strength

Velocity plateau observed in large DMI systems

Modeling extends understanding to cases with similar DMI and demagnetizing fields

Abstract

The domain wall dynamics driven by an out of plane magnetic field was measured for a series of magnetic trilayers with different strengths of the interfacial Dzyaloshinskii-Moriya interaction (DMI). The features of the field-driven domain wall velocity curves strongly depend on the amplitude of the HD field stabilising chiral N\'eel walls. The measured Walker velocity, which in systems with large DMI is maintained after the Walker field giving rise to a velocity plateau up to the Slonczewski field HS, can be easily related to the DMI strength. Yet, when the DMI field HD and the domain wall demagnetising field HDW have comparable values, a careful analysis needs to be done in order to evaluate the impact of the DMI on the domain wall velocity. By means of a one-dimensional model and 2D simulations, we successfully extend this method to explain experimental results to cases where HD and HDW are comparable.