Magnetic domain engineering in antiferromagnetic CuMnAs and Mn$_2$Au devices

TL;DR

This paper demonstrates methods to control and engineer magnetic domains in antiferromagnetic CuMnAs and Mn2Au devices using patterning and strain, revealing key parameters influencing domain formation.

Contribution

It introduces simple, functional techniques for manipulating antiferromagnetic domains via device patterning and strain, supported by a theoretical model explaining domain behavior.

Findings

Patterned edges significantly influence magnetic anisotropy and domain structure.

Magnetostriction, substrate clamping, and edge anisotropy interact to determine domain configurations.

The principles are broadly applicable to antiferromagnetic thin films.

Abstract

Antiferromagnetic materials hold potential for use in spintronic devices with fast operation frequencies and field robustness. Despite the rapid progress in proof-of-principle functionality in recent years, there has been a notable lack of understanding of antiferromagnetic domain formation and manipulation, which translates to either incomplete or non-scalable control of the magnetic order. Here, we demonstrate simple and functional ways of influencing the domain structure in CuMnAs and Mn2Au, two key materials of antiferromagnetic spintronics research, using device patterning and strain engineering. Comparing x-ray microscopy data from two different materials, we reveal the key parameters dictating domain formation in antiferromagnetic devices and show how the non-trivial interaction of magnetostriction, substrate clamping and edge anisotropy leads to specific equilibrium domain configurations. More specifically, we observe that patterned edges have a significant impact on the magnetic anisotropy and domain structure over long distances, and we propose a theoretical model that relates short-range edge anisotropy and long-range magnetoelastic interactions. The principles invoked are of general applicability to the domain formation and engineering in antiferromagnetic thin films at large, which will pave the way towards realizing truly functional antiferromagnetic devices.