  We calculated the polarization-dependent Raman scattering cross section
spectra of LaMnO3 below the A-type magnetic ordering temperature. Two strong
peaks appear around the MnO6 octahedra stretching phonon frequency. One mode
shows Ag symmetry, while the other mode shows Bg symmetry. We found that the Ag
symmetry peak is a Jahn-Teller phonon coupled to the orbital wave and the Bg
symmetry peak is an orbital wave coupled to a Q2 phonon mode via the
Jahn-Teller electron phonon coupling.
