title: Inelastic x-ray scattering in heterostructures: electronic excitations in LaAlO₃/SrTiO₃.
abstract: We present an investigation of the valence-electron excitation spectra including the collective plasmon modes of SrTiO3, LaAlO3 and their heterostructures with non-resonant inelastic x-ray scattering. We analyse the spectra using calculations based on first principles and atomic multiplet models. We demonstrate the feasibility of performing valence IXS experiments in a total reflection geometry. Surprisingly, we find that the plasmon, interband and semicore excitations in multilayers are well described as a superposition of bulk-compound spectra even in a superstructure composing of layers of only one atomic layer thickness.
authors.affiliation: Department of Physics, University of Helsinki, PO Box 64, FI-00014, Finland.
authors.forename: Kari O
authors.initials: KO
authors.lastname: Ruotsalainen
authors.forename: Christoph J
authors.initials: CJ
authors.lastname: Sahle
authors.forename: Tobias
authors.initials: T
authors.lastname: Ritschel
authors.forename: Jochen
authors.initials: J
authors.lastname: Geck
authors.forename: Masayuki
authors.initials: M
authors.lastname: Hosoda
authors.forename: Christopher
authors.initials: C
authors.lastname: Bell
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Hikita
authors.forename: Harold Y
authors.initials: HY
authors.lastname: Hwang
authors.forename: Tim T
authors.initials: TT
authors.lastname: Fister
authors.forename: Robert A
authors.initials: RA
authors.lastname: Gordon
authors.forename: Keijo
authors.initials: K
authors.lastname: Hämäläinen
authors.forename: Mikko
authors.initials: M
authors.lastname: Hakala
authors.forename: Simo
authors.initials: S
authors.lastname: Huotari