Non-polar electromagnon in hexa-YMnO$_{3}$

Coupled magnon-phonon excitations in magnetic materials have been observed in multiferroic materials and involve the polar optical phonons. Such excitations may be more general, occurring in non-ferroelectric magnets and involving non-polar (Raman or silent) phonons. Temperature-dependent Raman spectra of low-frequency excitations in single-crystal h-YMnO$_{3}$ are measured using a triple-grating spectrometer. We compare the spectral intensity of magnons to changes in the Raman-active phonons above and below the Neel temperature. Raman and infrared experimental results on h-YMnO3 demonstrate that the 5 meV hybrid mode observed in neutron scattering is an example of a Raman electromagnon.