Two-dimensional confinement of 3d{1} electrons in LaTiO_{3}/LaAlO{3} multilayers.
We report spectroscopic ellipsometry measurements of the anisotropy of the interband transitions parallel and perpendicular to the planes of (LaTiO3)n(LaAlO3)5 multilayers with n=1-3. These provide direct information about the electronic structure of the two-dimensional (2D) 3d{1} state of the Ti ions. In combination with local density approximation, including a Hubbard U calculation, we suggest that 2D confinement in the TiO2 slabs lifts the degeneracy of the t{2g} states leaving only the planar d{xy} orbitals occupied. We outline that these multilayers can serve as a model system for the study of the t{2g} 2D Hubbard model.
Seo
S S A
SS
Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea. seos@ornl.gov
Han
M J
MJ
Hassink
G W J
GW
Choi
W S
WS
Moon
S J
SJ
Kim
J S
JS
Susaki
T
T
Lee
Y S
YS
Yu
J
J
Bernhard
C
C
Hwang
H Y
HY
Rijnders
G
G
Blank
D H A
DH
Keimer
B
B
Noh
T W
TW