title: Evidence for a competition between the superconducting state and the pseudogap state of (BiPb)2(SrLa)2CuO6+delta from muon spin rotation experiments.
abstract: The in-plane magnetic penetration depth lambda ab in optimally doped (BiPb)2(SrLa)2CuO6+delta (OP Bi2201) was studied by means of muon-spin rotation. The measurements of lambda ab(-2)(T) are inconsistent with a simple model of a d-wave order parameter and a uniform quasiparticle weight around the Fermi surface. The data are well described assuming the angular gap symmetry obtained in ARPES experiments [Phys. Rev. Lett. 98, 267004 (2007)], which suggest that the superconducting gap in OP Bi2201 exists only in segments of the Fermi surface near the nodes. The remaining parts of the Fermi surface, which are strongly affected by the pseudogap state, do not contribute significantly to the superconducting condensate.
authors.affiliation: Laboratory for Muon Spin Spectroscopy, Paul Scherrer Institut, CH-5232 Villigen PSI, Switzerland. rustem.khasanov@psi.ch
authors.forename: R
authors.initials: R
authors.lastname: Khasanov
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kondo
authors.forename: S
authors.initials: S
authors.lastname: Strässle
authors.forename: D O G
authors.initials: DO
authors.lastname: Heron
authors.forename: A
authors.initials: A
authors.lastname: Kaminski
authors.forename: H
authors.initials: H
authors.lastname: Keller
authors.forename: S L
authors.initials: SL
authors.lastname: Lee
authors.forename: Tsunehiro
authors.initials: T
authors.lastname: Takeuchi