title: Orbital ordering in LaMnO3 investigated by resonance Raman spectroscopy.
abstract: Orbital ordering leads to an unconventional excitation spectrum that we investigate by resonance Raman scattering using incident photon energies between 1.7 and 5.0 eV. We use spectral ellipsometry to determine the corresponding dielectric function. Our results show resonant behavior of the phonon Raman cross section when the laser frequency is close to the orbiton-excitation energy of 2 eV in LaMnO3. We show an excellent agreement between theoretical calculations based on the Franck-Condon mechanism activating multiphonon Raman scattering in first order of the electron-phonon coupling and the experimental data of phonons with different symmetries.
authors.affiliation: Institut für Angewandte Physik, Universität Hamburg, Jungiusstrasse 9, D-20355 Hamburg, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Krüger
authors.forename: B
authors.initials: B
authors.lastname: Schulz
authors.forename: S
authors.initials: S
authors.lastname: Naler
authors.forename: R
authors.initials: R
authors.lastname: Rauer
authors.forename: D
authors.initials: D
authors.lastname: Budelmann
authors.forename: J
authors.initials: J
authors.lastname: Bäckström
authors.forename: K H
authors.initials: KH
authors.lastname: Kim
authors.forename: S-W
authors.initials: SW
authors.lastname: Cheong
authors.forename: V
authors.initials: V
authors.lastname: Perebeinos
authors.forename: M
authors.initials: M
authors.lastname: Rübhausen