Structure, control, and dynamics of altermagnetic textures

Bibliographic Details
Title: Structure, control, and dynamics of altermagnetic textures
Authors: Gomonay, O., Kravchuk, V. P., Jaeschke-Ubiergo, R., Yershov, K. V., Jungwirth, T., Šmejkal, L., Brink, J. van den, Sinova, J.
Source: npj Spintronics 2, 35 (2024)
Publication Year: 2024
Collection: Condensed Matter
Subject Terms: Condensed Matter - Mesoscale and Nanoscale Physics
More Details: We present a phenomenological theory of altermagnets, that captures their unique magnetization dynamics and allows modelling magnetic textures in this new magnetic phase. Focusing on the prototypical d-wave altermagnets, e.g. RuO$_2$, we can explain intuitively the characteristic lifted degeneracy of their magnon spectra, by the emergence of an effective sublattice-dependent anisotropic spin stiffness arising naturally from the phenomenological theory. We show that as a consequence the altermagnetic domain walls, in contrast to antiferromagnets, have a finite gradient of the magnetization, with its strength and gradient direction connected to the altermagnetic anisotropy, even for 180$^\circ$ domain walls. This gradient generates a ponderomotive force in the domain wall in the presence of a strongly inhomogeneous external magnetic field, which may be achieved through magnetic force microscopy techniques. The motion of these altermagentic domain walls is also characterized by an anisotropic Walker breakdown, with much higher speed limits of propagation than ferromagnets but lower than antiferromagnets.
Document Type: Working Paper
DOI: 10.1038/s44306-024-00042-3
Access URL: http://arxiv.org/abs/2403.10218
Accession Number: edsarx.2403.10218
Database: arXiv
More Details
DOI:10.1038/s44306-024-00042-3