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  • Open Access

Spontaneous magnon decay in two-dimensional altermagnets

Niklas Cichutek, Peter Kopietz, and Andreas Rückriegel*

  • Institut für Theoretische Physik, Universität Frankfurt, Max-von-Laue Straße 1, 60438 Frankfurt, Germany

  • *Contact author: rueckriegel@itp.uni-frankfurt.de
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Phys. Rev. Research 7, 033208 – Published 2 September, 2025

DOI: https://doi.org/10.1103/b5vs-ldpm

Abstract

We show that magnons in two-dimensional altermagnets can spontaneously decay at zero temperature. The decay rate is determined by quantum fluctuations and scattering processes involving the decay of a single magnon into three. These processes are kinematically allowed due to the convexity of the altermagnetic magnon dispersion. For small wave vectors k, the decay rate is proportional to k5 with a direction-dependent prefactor, which is maximal along the diagonals of the Brillouin zone. Moreover, for a given momentum only magnons with one specific chirality can spontaneously decay.

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References (21)

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Phys. Rev. Research 7, 033208– Published 2 September, 2025
  • Received 7 March 2025
  • Accepted 14 July 2025
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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