Spontaneous magnon decay in two-dimensional altermagnets

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 wavevectors $k$ the decay rate is proportional to $k^5$ 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.

5 pages, 5 figures

References in corpus (5)

• Altermagnetism: spin-momentum locked phase protected by non-relativistic symmetries
• Spontaneous Magnon Decays
• Two-dimensional altermagnets: Superconductivity in a minimal microscopic model
• Magnon spectrum of altermagnets beyond linear spin wave theory: Magnon-magnon interactions via time-dependent matrix product states vs. atomistic spin dynamics
• SU($N$) altermagnetism: Lattice models, magnon modes, and flavor-split bands

Cited by in corpus (4)

• Systematic Mapping of Altermagnetic Magnons by Resonant Inelastic X-Ray Circular Dichroism
• Quantum fluctuations in two-dimensional altermagnets
• Quantum effects in the magnon spectrum of 2D altermagnets via continuous similarity transformations
• Nonlinear opto-magnetic signature of d-wave altermagnets