Magnetic excitations in the low-temperature ferroelectric phase of multiferroic YMn₂O₅ using inelastic neutron scattering

We studied magnetic excitations in a low-temperature ferroelectric phase of the multiferroic YMn₂O₅ using inelastic neutron scattering (INS). We identify low-energy magnon modes and establish a correspondence between the magnon peaks observed by INS and electromagnon peaks observed in optical absorption. Furthermore, we explain the microscopic mechanism, which results in the lowest-energy electromagnon peak, by comparing the inelastic neutron spectral weight with the polarization in the commensurate ferroelectric phase.