title: ARPES on Na0.6CoO2: Fermi surface and unusual band dispersion.
abstract: The electronic structure of single crystals Na0.6CoO2, which are closely related to the superconducting Na0.3CoO2.yH(2)O (T(c) approximately 5 K), is studied by angle-resolved photoelectron spectroscopy. While the measured Fermi surface (FS) is consistent with the large FS enclosing the Gamma point from the band theory, the predicted small FS pockets near the K points are absent. In addition, the band dispersion is found to be highly renormalized, and anisotropic along the two principal axes (Gamma-K, Gamma-M). Our measurements also indicate that an extended flatband is formed slightly above E(F) along Gamma-K.
authors.affiliation: Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467, USA.
authors.forename: H-B
authors.initials: HB
authors.lastname: Yang
authors.forename: S-C
authors.initials: SC
authors.lastname: Wang
authors.forename: A K P
authors.initials: AK
authors.lastname: Sekharan
authors.forename: H
authors.initials: H
authors.lastname: Matsui
authors.forename: S
authors.initials: S
authors.lastname: Souma
authors.forename: T
authors.initials: T
authors.lastname: Sato
authors.forename: T
authors.initials: T
authors.lastname: Takahashi
authors.forename: T
authors.initials: T
authors.lastname: Takeuchi
authors.forename: J C
authors.initials: JC
authors.lastname: Campuzano
authors.forename: R
authors.initials: R
authors.lastname: Jin
authors.forename: B C
authors.initials: BC
authors.lastname: Sales
authors.forename: D
authors.initials: D
authors.lastname: Mandrus
authors.forename: Z
authors.initials: Z
authors.lastname: Wang
authors.forename: H
authors.initials: H
authors.lastname: Ding