Strain-driven domain wall network with chiral junctions in an antiferromagnet

TL;DR

This paper demonstrates how local strain in a collinear antiferromagnet can create complex domain wall networks with chiral junctions, enabling potential spintronic applications involving topological magnetic states.

Contribution

It introduces a method to engineer non-coplanar domain wall networks with chiral junctions in antiferromagnets using local strain, combining experimental and theoretical analysis.

Findings

Strain induces non-coplanar domain wall junctions in antiferromagnets.

Chiral properties of junctions are characterized and linked to their topological moments.

The origin of junction handedness is explained through combined microscopy and DFT analysis.

Abstract

Materials with antiferromagnetic order have recently emerged as promising candidates in spintronics based on their beneficial characteristics such as vanishing stray fields and ultra-fast dynamics. At the same time more complex localized non-coplanar magnetic states as for instance skyrmions are in the focus of applications due to their intriguing properties such as the topological Hall effect. Recently a conceptual shift has occurred to envision the use of such magnetic defects not only in one-dimensional race track devices but to exploit their unique properties in two-dimensional networks. Here we use local strain in a collinear antiferromagnet to induce non-coplanar domain wall junctions, which connect in a very specific way to form extended networks. We combine spin-polarized scanning tunneling microscopy with density functional theory to characterize the different building blocks of the network, and unravel the origin of the handedness of triple-junctions and the size of the arising topological orbital moments.