Research: Structure, control, and dynamics of altermagnetic textures

Altermagnets, a recently discovered third fundamental class of collinear magnetic order, are the subject of rapidly growing interest in the solid-state community. While similar to conventional collinear antiferromagnets, altermagnets differ fundamentally from the latter in that rotation is included in the symmetry operation connecting the two sublattices. This difference leads to a specific splitting of the electron and magnon spectra, which is a distinctive feature of altermagnetic materials. Here we have developed a general approach for dealing with non-collinear magnetic structures in altermagnets and applied it to reveal new features in the statics and dynamics of domain walls. We found that nonuniformity of the order parameter (Neel vector) is a source of the local magnetization in altermagnets. The effect is maximal when the gradients are oriented in the direction of the maximum spectral splitting. It can be used to detect the domain walls experimentally. Also, a moving altermagnetic domain wall gains additional deformation which leads to the Walker breakdown in the high-velocity regime.

O. Gomonay, V. P. Kravchuk, R. Jaeschke-Ubiergo, K. V. Yershov, T. Jungwirth, L. Šmejkal, J. van den Brink, J. Sinova,
Structure, control, and dynamics of altermagnetic textures,
npj Spintronics 2, 35 (2024) (arXiv)