Interplay of anisotropic paramagnons and polarons in altermagnetic MnTe

Altermagnets can exhibit an unusual d– or g–wave magnetization order parameter due to their combined breaking of rotational and time-reversal symmetry, which is explained by multipolar magnetic moments. MnTe is an altermagnet candidate with large spin, S=5/2, and correspondingly strong magnetic neutron scattering signal. Recent inelastic neutron scattering work observed chirally split magnons in MnTe. Furthermore, theory work suggested coupling between the altermagnetic order parameter and the lattice dynamics, even in the absence of a magnetic field. This coupling would lead to a hybridized paramagnon-polaron mode that provides direct access to altermagnetic excitations based on phonon data. We will report on a study of the chiral magnon modes and their interplay with phonons. This work was carried out with triple-axis neutron spectroscopy and reveals different dynamical structure factors for the transverse and longitudinal paramagnon-polaron interactions.