We present a theory of the collective orbital excitation termed orbital wave in perovskite titanates and vanadates with the triply degenerate t2g orbitals. The dispersion relations of the orbital waves for the orbital-ordered LaVO3, YVO3 and YTiO3 are examined in the effective spin-orbital coupled Hamiltonians associated with the Jahn-Teller type couplings. We propose possible scattering processes for the Raman and inelastic neutron scatterings from the orbital wave and calculate the scattering spectra for titanates and vanadates. It is found that both the excitation spectra and the observation methods of the orbital wave are distinct qualitatively from those for the eg orbital-ordered systems.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2004 Feb 27|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics