title: Photoemission from buried interfaces in SrTiO3/LaTiO3 superlattices.
abstract: We have measured photoemission spectra of SrTiO3/LaTiO3 superlattices with a topmost SrTiO3 layer of variable thickness. A finite coherent spectral weight with a clear Fermi cutoff was observed at chemically abrupt SrTiO3/LaTiO3 interfaces, indicating that an "electronic reconstruction" occurs at the interface between the Mott insulator LaTiO3 and the band insulator SrTiO3. For SrTiO3/LaTiO3 interfaces annealed at high temperatures (approximately 1000 degrees C), which leads to Sr/La atomic interdiffusion and hence to the formation of La(1-x)Sr(x)TiO3-like material, the intensity of the incoherent part was found to be dramatically reduced whereas the coherent part with a sharp Fermi cutoff was enhanced due to the spread of charge. These important experimental features are well reproduced by layer dynamical-mean-field-theory calculation.
authors.affiliation: Department of Physics and Department of Complexity Science and Engineering, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwashi, Chiba 277-8561, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Takizawa
authors.forename: H
authors.initials: H
authors.lastname: Wadati
authors.forename: K
authors.initials: K
authors.lastname: Tanaka
authors.forename: M
authors.initials: M
authors.lastname: Hashimoto
authors.forename: T
authors.initials: T
authors.lastname: Yoshida
authors.forename: A
authors.initials: A
authors.lastname: Fujimori
authors.forename: A
authors.initials: A
authors.lastname: Chikamatsu
authors.forename: H
authors.initials: H
authors.lastname: Kumigashira
authors.forename: M
authors.initials: M
authors.lastname: Oshima
authors.forename: K
authors.initials: K
authors.lastname: Shibuya
authors.forename: T
authors.initials: T
authors.lastname: Mihara
authors.forename: T
authors.initials: T
authors.lastname: Ohnishi
authors.forename: M
authors.initials: M
authors.lastname: Lippmaa
authors.forename: M
authors.initials: M
authors.lastname: Kawasaki
authors.forename: H
authors.initials: H
authors.lastname: Koinuma
authors.forename: S
authors.initials: S
authors.lastname: Okamoto
authors.forename: A J
authors.initials: AJ
authors.lastname: Millis