Effects of magnon-magnon interactions on the magnon spectrum of 2D altermagnets

Wiedmann R, Hering DB, Sulaiman V, Walther M, Schmidt KP, Uhrig GS (2026)

Publication Type: Journal article

Publication year: 2026

Book Volume: 4

Article Number: 26

Journal Issue: 1

DOI: 10.1038/s44306-026-00144-0

Abstract

We investigate interaction effects on magnon excitations in a minimal spin-1/2 Heisenberg model for 2D altermagnets on the square lattice. A continuous similarity transformation is applied in momentum space to derive an effective Hamiltonian that conserves the number of magnon excitations. This allows us to quantitatively calculate the one-magnon dispersion, the effects of magnon-magnon interactions, and the dynamic structure factor in a certain range of parameters. In particular, we focus on the altermagnetic spin splitting of the magnon bands and the size of the roton minimum. We further map out divergencies of the continuous similarity transformation for different types of generators, which signal either the breakdown of the Néel-ordered phase or the presence of significant magnon decay.

Authors with CRIS profile

Matthias Walther Lehrstuhl für Theoretische Physik Kai Phillip Schmidt Professur für Theoretische Physik

Involved external institutions

Max-Planck-Institut für Festkörperforschung DE Germany (DE) Technische Universität Dortmund DE Germany (DE)

How to cite

APA:

Wiedmann, R., Hering, D.B., Sulaiman, V., Walther, M., Schmidt, K.P., & Uhrig, G.S. (2026). Effects of magnon-magnon interactions on the magnon spectrum of 2D altermagnets. , 4(1). https://doi.org/10.1038/s44306-026-00144-0

MLA:

Wiedmann, Raymond, et al. "Effects of magnon-magnon interactions on the magnon spectrum of 2D altermagnets." 4.1 (2026).

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