Accurate chiral magnon splitting in altermagnetic MnTe fully from first principles

Altermagnets are gaining attention for their unique properties in spintronics. Yet, accurate ab initio simulations of their magnon excitations remain challenging, with most studies relying on model Hamiltonians with empirical input. Here, we present fully first-principles calculations of the magnon dispersion in MnTe, a prototypical insulating altermagnet recently shown to host chiral magnon splitting [1]. Using our newly developed time-dependent density-functional perturbation theory with self-consistent ab initio Hubbard U (TDDFPT+U) [2], we describe the spin-wave spectrum without adjustable parameters. The results show excellent agreement with neutron scattering experiments, accurately reproducing both the magnon dispersion and the subtle chiral splitting. We further predict the evolution of magnon modes under pressure, offering insights into regimes beyond current experimental reach. Our work opens the door to reliable investigations of chiral magnons in altermagnets.

[1] Z. Liu et al., PRL 133, 156702 (2024).

[2] L. Binci et al., npj Comput. Mater. 11, 100 (2025).