title: Orbital excitations in LaMnO3.
abstract: We study the recently observed orbital excitations, orbitons, and treat electron-electron correlations and lattice dynamics on an equal footing. It is shown that the orbiton energy and dispersion are determined by both correlations and lattice vibrations. The electron-phonon coupling causes satellite structures in the orbiton spectral function and the elementary excitations of the system are mixed modes with both orbital and phonon character. It is proposed that the satellite structures observed in recent Raman-scattering experiments on LaMnO3 are actually orbiton derived satellites in the phonon spectral function, caused by the phonon-orbiton interaction.
authors.affiliation: Computational Materials Science and MESA+ Institute, Faculty of Applied Physics, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: van den Brink