Dynamic imaging of an antiferromagnetic domain wall via quantum-impurity relaxometry

TL;DR

This paper introduces quantum relaxometry as a novel method to image and analyze the dynamic spin textures of antiferromagnetic domain walls by detecting their collective spin modes with quantum sensors.

Contribution

It proposes a new quantum relaxometry technique to detect antiferromagnetic domain wall spin textures and their collective modes, enabling detailed dynamic imaging.

Findings

Goldstone modes in antiferromagnetic domain walls can be detected via relaxometry.

A protocol is proposed to probe individual mode dynamics.

Quantum sensors can detect collective spin modes in common antiferromagnets.

Abstract

While spin textures in materials exhibiting zero net magnetization, such as antiferromagnetic domain walls (DWs), have attracted much interest lately due to their robustness against external magnetic noise, their generic detection via conventional magnetometry remains a challenging task. Here, we propose quantum relaxometry as a new route to image spin textures by probing the collective spin modes harbored by them. We investigate the Goldstone modes hosted by an antiferromagnetic domain wall and assess the relaxation rate of a quantum-spin sensor interacting with them. We show that such modes can be detected via relaxometry in some common antiferromagnets. Moreover, based on symmetry considerations, we propose a simple protocol to probe the individual dynamics of each mode.