title: Dimensionality-controlled insulator-metal transition and correlated metallic state in 5d transition metal oxides Sr n+1Ir nO3n+1 (n=1, 2, and infinity).
abstract: We investigated the electronic structures of the 5d Ruddlesden-Popper series Sr n+1Ir nO3n+1 (n=1, 2, and infinity) using optical spectroscopy and first-principles calculations. As 5d orbitals are spatially more extended than 3d or 4d orbitals, it has been widely accepted that correlation effects are minimal in 5d compounds. However, we observed a Mott insulator-metal transition with a change of bandwidth as we increased n. In addition, the artificially synthesized perovskite SrIrO3 showed a very large mass enhancement of about 6, indicating that it was in a correlated metallic state.
authors.affiliation: ReCOE & FPRD, Department of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea.
authors.forename: S J
authors.initials: SJ
authors.lastname: Moon
authors.forename: H
authors.initials: H
authors.lastname: Jin
authors.forename: K W
authors.initials: KW
authors.lastname: Kim
authors.forename: W S
authors.initials: WS
authors.lastname: Choi
authors.forename: Y S
authors.initials: YS
authors.lastname: Lee
authors.forename: J
authors.initials: J
authors.lastname: Yu
authors.forename: G
authors.initials: G
authors.lastname: Cao
authors.forename: A
authors.initials: A
authors.lastname: Sumi
authors.forename: H
authors.initials: H
authors.lastname: Funakubo
authors.forename: C
authors.initials: C
authors.lastname: Bernhard
authors.forename: T W
authors.initials: TW
authors.lastname: Noh