Probing the Spin-dynamics in an Altermagnetic Candidate

Altermagnetism which features vanishing net magnetization and time-reversal symmetry broken electronic structures has been identified to be the third ground state of collinear magnetism. Similar to the electronic structure, the degeneracy of magnon bands with opposite chirality is predicted to be lifted. Probing the chiral splitting magnon band would be a direct experimental verification of an altermagnetic phase. MnTe with a hexagonal NiAs-type structure is an altermagnetic candidate. Previous study of MnTe has reported observation of a spontaneous anomalous Hall effect and the spin-split electronic structure revealed by angle-resolved photoemission spectroscopy. However, direct verification of altermagnetic states via neutron spectroscopic methods, e.g., measuring the chiral-split magnon bands by inelastic neutron scattering (INS), is still lacking. Therefore, INS data is imperatively needed.