Momentum dependence of orbital excitations in Mott-insulating titanates.
High-resolution resonant inelastic x-ray scattering has been used to determine the momentum dependence of orbital excitations in Mott-insulating LaTiO(3) and YTiO(3) over a wide range of the Brillouin zone. The data are compared to calculations in the framework of lattice-driven and superexchange-driven orbital ordering models. A superexchange model in which the experimentally observed modes are attributed to two-orbiton excitations yields the best description of the data.
Max-Planck-Institut für Festkörperforschung, D-70569 Stuttgart, Germany.
C
C
Ulrich
L J P
LJ
Ament
G
G
Ghiringhelli
L
L
Braicovich
M
M
Moretti Sala
N
N
Pezzotta
T
T
Schmitt
G
G
Khaliullin
J
J
van den Brink
H
H
Roth
T
T
Lorenz
B
B
Keimer