title: de Haas-van Alphen study of the Fermi surfaces of superconducting LiFeP and LiFeAs.
abstract: We report a de Haas-van Alphen oscillation study of the 111 iron pnictide superconductors LiFeAs with T(c) ≈ 18 K and LiFeP with T(c) ≈ 5 K. We find that for both compounds the Fermi surface topology is in good agreement with density functional band-structure calculations and has almost nested electron and hole bands. The effective masses generally show significant enhancement, up to ~3 for LiFeP and ~5 for LiFeAs. However, one hole Fermi surface in LiFeP shows a very small enhancement, as compared with its other sheets. This difference probably results from k-dependent coupling to spin fluctuations and may be the origin of the different nodal and nodeless superconducting gap structures in LiFeP and LiFeAs, respectively.
authors.affiliation: HH Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, United Kingdom.
authors.forename: C
authors.initials: C
authors.lastname: Putzke
authors.forename: A I
authors.initials: AI
authors.lastname: Coldea
authors.forename: I
authors.initials: I
authors.lastname: Guillamón
authors.forename: D
authors.initials: D
authors.lastname: Vignolles
authors.forename: A
authors.initials: A
authors.lastname: McCollam
authors.forename: D
authors.initials: D
authors.lastname: Leboeuf
authors.forename: M D
authors.initials: MD
authors.lastname: Watson
authors.forename: I I
authors.initials: II
authors.lastname: Mazin
authors.forename: S
authors.initials: S
authors.lastname: Kasahara
authors.forename: T
authors.initials: T
authors.lastname: Terashima
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