title: Novel Jeff=1/2 Mott state induced by relativistic spin-orbit coupling in Sr2IrO4.
abstract: We investigated the electronic structure of 5d transition-metal oxide Sr2IrO4 using angle-resolved photoemission, optical conductivity, x-ray absorption measurements, and first-principles band calculations. The system was found to be well described by novel effective total angular momentum Jeff states, in which the relativistic spin-orbit coupling is fully taken into account under a large crystal field. Despite delocalized Ir 5d states, the Jeff states form such narrow bands that even a small correlation energy leads to the Jeff=1/2 Mott ground state with unique electronic and magnetic behaviors, suggesting a new class of Jeff quantum spin driven correlated-electron phenomena.
authors.affiliation: School of Physics and Astronomy, Seoul National University, Seoul 151-747, Korea.
authors.forename: B J
authors.initials: BJ
authors.lastname: Kim
authors.forename: Hosub
authors.initials: H
authors.lastname: Jin
authors.forename: S J
authors.initials: SJ
authors.lastname: Moon
authors.forename: J-Y
authors.initials: JY
authors.lastname: Kim
authors.forename: B-G
authors.initials: BG
authors.lastname: Park
authors.forename: C S
authors.initials: CS
authors.lastname: Leem
authors.forename: Jaejun
authors.initials: J
authors.lastname: Yu
authors.forename: T W
authors.initials: TW
authors.lastname: Noh
authors.forename: C
authors.initials: C
authors.lastname: Kim
authors.forename: S-J
authors.initials: SJ
authors.lastname: Oh
authors.forename: J-H
authors.initials: JH
authors.lastname: Park
authors.forename: V
authors.initials: V
authors.lastname: Durairaj
authors.forename: G
authors.initials: G
authors.lastname: Cao
authors.forename: E
authors.initials: E
authors.lastname: Rotenberg