title: Anomalies in the Fermi surface and band dispersion of quasi-one-dimensional CuO chains in the high-temperature superconductor YBa2Cu4O8.
abstract: We have investigated the electronic states in quasi-one-dimensional CuO chains by microprobe angle resolved photoemission spectroscopy. We find that the quasiparticle Fermi surface consists of six disconnected segments, consistent with recent theoretical calculations that predict the formation of narrow, elongated Fermi surface pockets for coupled CuO chains. In addition, we find a strong renormalization effect with a significant kink structure in the band dispersion. The properties of this latter effect [energy scale (∼40 meV), temperature dependence, and behavior with Zn-doping] are identical to those of the bosonic mode observed in CuO2 planes of high-temperature superconductors, indicating they have a common origin.
authors.affiliation: Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kondo
authors.forename: R
authors.initials: R
authors.lastname: Khasanov
authors.forename: J
authors.initials: J
authors.lastname: Karpinski
authors.forename: S M
authors.initials: SM
authors.lastname: Kazakov
authors.forename: N D
authors.initials: ND
authors.lastname: Zhigadlo
authors.forename: Z
authors.initials: Z
authors.lastname: Bukowski
authors.forename: M
authors.initials: M
authors.lastname: Shi
authors.forename: A
authors.initials: A
authors.lastname: Bendounan
authors.forename: Y
authors.initials: Y
authors.lastname: Sassa
authors.forename: J
authors.initials: J
authors.lastname: Chang
authors.forename: S
authors.initials: S
authors.lastname: Pailhés
authors.forename: J
authors.initials: J
authors.lastname: Mesot
authors.forename: J
authors.initials: J
authors.lastname: Schmalian
authors.forename: H
authors.initials: H
authors.lastname: Keller
authors.forename: A
authors.initials: A
authors.lastname: Kaminski