Nanoscale mechanics of antiferromagnetic domain walls

Abstract

Antiferromagnets can encode information in their ordered magnetic structure, providing the basis for future spintronic devices1–3. The control and understanding of antiferromagnetic domain walls, which are the interfaces between domains with differing order parameter orientations, are key ingredients for advancing antiferromagnetic spintronic technologies. However, studies of the intrinsic mechanics of individual antiferromagnetic domain walls are difficult because they require sufficiently pure materials and suitable experimental approaches to address domain walls on the nanoscale. Here we nucleate isolated 180° domain walls in a single crystal of Cr2O3, a prototypical collinear magnetoelectric antiferromagnet, and study their interaction with topographic features fabricated on the sample. We demonstrate domain wall manipulation through the resulting engineered energy landscape and show that the observed interaction is governed by the surface energy of the domain wall. We propose a topographically defined memory architecture based on antiferromagnetic domain walls. Our results advance the understanding of domain wall mechanics in antiferromagnets. High-resolution magnetometry shows that the shape of domain walls in Cr2O3 is determined by the energetic cost of their surface area. The walls behave like elastic surfaces that avoid thicker parts of the sample where they would need to be larger.

Cite this article

Hedrich, N., Wagner, K., Pylypovskyi, O.V. et al. Nanoscale mechanics of antiferromagnetic domain walls. Nat. Phys. (2021). https://doi.org/10.1038/s41567-020-01157-0

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