title: Local quasiparticle density of states of superconducting SmFeAsO(1-x)F(x) single crystals: evidence for spin-mediated pairing.
abstract: We probe the local quasiparticles density of states in micron-sized SmFeAsO(1-x)F(x) single crystals by means of scanning tunnelling spectroscopy. Spectral features resemble those of cuprates, particularly a dip-hump-like structure developed at energies larger than the gap that can be ascribed to the coupling of quasiparticles to a collective mode, quite likely a resonant spin mode. The energy of the collective mode revealed in our study decreases when the pairing strength increases. Our findings support spin-fluctuation-mediated pairing in pnictides.
authors.affiliation: DPMC-MaNEP, University of Geneva, Geneva, Switzerland.
authors.forename: Y
authors.initials: Y
authors.lastname: Fasano
authors.forename: I
authors.initials: I
authors.lastname: Maggio-Aprile
authors.forename: N D
authors.initials: ND
authors.lastname: Zhigadlo
authors.forename: S
authors.initials: S
authors.lastname: Katrych
authors.forename: J
authors.initials: J
authors.lastname: Karpinski
authors.forename: Ø
authors.initials: Ø
authors.lastname: Fischer