title: Two-dimensional confinement of 3d{1} electrons in LaTiO_{3}/LaAlO{3} multilayers.
abstract: 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.
authors.affiliation: Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea. seos@ornl.gov
authors.forename: S S A
authors.initials: SS
authors.lastname: Seo
authors.forename: M J
authors.initials: MJ
authors.lastname: Han
authors.forename: G W J
authors.initials: GW
authors.lastname: Hassink
authors.forename: W S
authors.initials: WS
authors.lastname: Choi
authors.forename: S J
authors.initials: SJ
authors.lastname: Moon
authors.forename: J S
authors.initials: JS
authors.lastname: Kim
authors.forename: T
authors.initials: T
authors.lastname: Susaki
authors.forename: Y S
authors.initials: YS
authors.lastname: Lee
authors.forename: J
authors.initials: J
authors.lastname: Yu
authors.forename: C
authors.initials: C
authors.lastname: Bernhard
authors.forename: H Y
authors.initials: HY
authors.lastname: Hwang
authors.forename: G
authors.initials: G
authors.lastname: Rijnders
authors.forename: D H A
authors.initials: DH
authors.lastname: Blank
authors.forename: B
authors.initials: B
authors.lastname: Keimer
authors.forename: T W
authors.initials: TW
authors.lastname: Noh