Current-induced fragmentation of antiferromagnetic domains

TL;DR

This study demonstrates that electrical pulsing causes nano-scale fragmentation of antiferromagnetic domains in CuMnAs, which correlates with large resistive switching signals, offering insights for spintronic memory and neuromorphic applications.

Contribution

It reveals that current-induced domain fragmentation occurs independently of current direction and is linked to resistive switching, advancing understanding of antiferromagnetic domain dynamics.

Findings

Nano-scale domain fragmentation controlled by current amplitude.

Fragmented domains retain memory of original patterns.

Correlation between domain fragmentation and resistive switching signals.

Abstract

Electrical and optical pulsing allow for manipulating the order parameter and magnetoresistance of antiferromagnets, opening novel prospects for digital and analog data storage in spintronic devices. Recent experiments in CuMnAs have demonstrated giant resistive switching signals in single-layer antiferromagnetic films together with analog switching and relaxation characteristics relevant for neuromorphic computing. Here we report simultaneous electrical pulsing and scanning NV magnetometry of antiferromagnetic domains in CuMnAs performed using a pump-probe scheme. We observe a nano-scale fragmentation of the antiferromagnetic domains, which is controlled by the current amplitude and independent on the current direction. The fragmented antiferromagnetic state conserves a memory of the pristine domain pattern, towards which it relaxes. Domain fragmentation coexists with permanent switching due to the reorientation of the antiferromagnetic moments. Our simultaneous imaging and resistance measurements show a correlation between the antiferromagnetic domain fragmentation and the largest resistive switching signals in CuMnAs.