title: Temperature and doping-dependent renormalization effects of the low energy electronic structure of Ba1-xKxFe2As2 single crystals.
abstract: We investigate the low energy electronic structure of Ba1-xKxFe2As2 (x=0; 0.3, T_{c}=32 K) single crystals by angle-resolved photoemission spectroscopy with a focus on the renormalization of the dispersion. A kink feature is detected at E approximately 25 meV for the doped compound which vanishes at T=200 K but stays virtually constant when T_{c} is crossed. Our experimental findings rule out the magnetic resonance mode as the origin of the kink and render conventional electron-phonon coupling unlikely. They put stringent restrictions on the dominant source of the electronic interaction channel.
authors.affiliation: Institute for Solid State Research, IFW-Dresden, P.O.Box 270116, D-01171 Dresden, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Koitzsch
authors.forename: D S
authors.initials: DS
authors.lastname: Inosov
authors.forename: D V
authors.initials: DV
authors.lastname: Evtushinsky
authors.forename: V B
authors.initials: VB
authors.lastname: Zabolotnyy
authors.forename: A A
authors.initials: AA
authors.lastname: Kordyuk
authors.forename: A
authors.initials: A
authors.lastname: Kondrat
authors.forename: C
authors.initials: C
authors.lastname: Hess
authors.forename: M
authors.initials: M
authors.lastname: Knupfer
authors.forename: B
authors.initials: B
authors.lastname: Büchner
authors.forename: G L
authors.initials: GL
authors.lastname: Sun
authors.forename: V
authors.initials: V
authors.lastname: Hinkov
authors.forename: C T
authors.initials: CT
authors.lastname: Lin
authors.forename: A
authors.initials: A
authors.lastname: Varykhalov
authors.forename: S V
authors.initials: SV
authors.lastname: Borisenko