Current-induced domain wall motion in compensated ferrimagnet

TL;DR

This study investigates current-induced domain wall motion in compensated ferrimagnets, revealing high mobility near angular momentum compensation and insights into domain wall structures, which could advance high-speed spintronics.

Contribution

It provides experimental and theoretical insights into domain wall dynamics in antiferromagnetically coupled systems, highlighting the role of sublattice spin orientations in Dzyaloshinskii-Moriya interactions.

Findings

Maximum domain wall mobility near angular momentum compensation

Chirality of domain walls remains consistent across compensation points

Potential for high-speed spintronic device applications

Abstract

Due to the difficulty in detecting and manipulating magnetic states of antiferromagnetic materials, studying their switching dynamics using electrical methods remains a challenging task. In this work, by employing heavy metal/rare earth-transition metal alloy bilayers, we experimentally studied current-induced domain wall dynamics in an antiferromagnetically coupled system. We show that the current-induced domain wall mobility reaches a maximum close to the angular momentum compensation. With experiment and modelling, we further reveal the internal structures of domain walls and the underlying mechanisms for their fast motion. We show that the chirality of the ferrimagnetic domain walls remains the same across the compensation points, suggesting that spin orientations of specific sublattices rather than net magnetization determine Dzyaloshinskii-Moriya interaction in heavy metal/ferrimagnet bilayers. The high current-induced domain wall mobility and the robust domain wall chirality in compensated ferrimagnetic material opens new opportunities for high-speed spintronic devices.