Scanning tunneling spectroscopy of superconducting LiFeAs single crystals: evidence for two nodeless energy gaps and coupling to a bosonic mode.

نویسندگان

  • Shun Chi
  • S Grothe
  • Ruixing Liang
  • P Dosanjh
  • W N Hardy
  • S A Burke
  • D A Bonn
  • Y Pennec
چکیده

The superconducting compound LiFeAs is studied by scanning tunneling microscopy and spectroscopy. A gap map of the unreconstructed surface indicates a high degree of homogeneity in this system. Spectra at 2 K show two nodeless superconducting gaps with Δ(1)=5.3±0.1 meV and Δ(2)=2.5±0.2 meV. The gaps close as the temperature is increased to the bulk T(c), indicating that the surface accurately represents the bulk. A dip-hump structure is observed below T(c) with an energy scale consistent with a magnetic resonance recently reported by inelastic neutron scattering.

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عنوان ژورنال:
  • Physical review letters

دوره 109 8  شماره 

صفحات  -

تاریخ انتشار 2012