Raman scattering in the Mott insulators LaTiO3 and YTiO3: evidence for orbital excitations.
Raman scattering is used to observe pronounced electronic excitations around 230 meV--well above the two-phonon range--in the Mott insulators LaTiO3 and YTiO3. Based on the temperature, polarization, and photon energy dependence, the modes are identified as orbital excitations. The observed profiles bear a striking resemblance to magnetic Raman modes in the insulating parent compounds of the superconducting cuprates, indicating an unanticipated universality of the electronic excitations in transition metal oxides.
Ulrich
C
C
Max-Planck-Institut für Festkörperforschung, Heisenbergstrasse 1, D-70569 Stuttgart, Germany.
Gössling
A
A
Grüninger
M
M
Guennou
M
M
Roth
H
H
Cwik
M
M
Lorenz
T
T
Khaliullin
G
G
Keimer
B
B