title: Quasiparticle mass enhancement close to the quantum critical point in BaFe2(As(1-x)P(x))2.
abstract: We report a combined study of the specific heat and de Haas-van Alphen effect in the iron-pnictide superconductor BaFe2(As(1-x)P(x))2. Our data when combined with results for the magnetic penetration depth give compelling evidence for the existence of a quantum critical point close to x=0.30 which affects the majority of the Fermi surface by enhancing the quasiparticle mass. The results show that the sharp peak in the inverse superfluid density seen in this system results from a strong increase in the quasiparticle mass at the quantum critical point.
authors.affiliation: H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, United Kingdom.
authors.forename: P
authors.initials: P
authors.lastname: Walmsley
authors.forename: C
authors.initials: C
authors.lastname: Putzke
authors.forename: L
authors.initials: L
authors.lastname: Malone
authors.forename: I
authors.initials: I
authors.lastname: Guillamón
authors.forename: D
authors.initials: D
authors.lastname: Vignolles
authors.forename: C
authors.initials: C
authors.lastname: Proust
authors.forename: S
authors.initials: S
authors.lastname: Badoux
authors.forename: A I
authors.initials: AI
authors.lastname: Coldea
authors.forename: M D
authors.initials: MD
authors.lastname: Watson
authors.forename: S
authors.initials: S
authors.lastname: Kasahara
authors.forename: Y
authors.initials: Y
authors.lastname: Mizukami
authors.forename: T
authors.initials: T
authors.lastname: Shibauchi
authors.forename: Y
authors.initials: Y
authors.lastname: Matsuda
authors.forename: A
authors.initials: A
authors.lastname: Carrington