Anisotropic electron-phonon coupling and dynamical nesting on the graphene sheets in superconducting CaC6 using angle-resolved photoemission spectroscopy.

نویسندگان

  • T Valla
  • J Camacho
  • Z-H Pan
  • A V Fedorov
  • A C Walters
  • C A Howard
  • M Ellerby
چکیده

We present the first angle-resolved photoemission studies of electronic structure in CaC6, a superconducting graphite intercalation compound with T_{c}=11.6 K. We find that, contrary to theoretical models, the electron-phonon coupling on the graphene-derived Fermi sheets with high-frequency graphene-derived phonons is surprisingly strong and anisotropic. The shape of the Fermi surface is found to favor a dynamical intervalley nesting via exchange of high-frequency phonons. Our results suggest that graphene sheets play a crucial role in superconductivity in graphite intercalation compounds.

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عنوان ژورنال:
  • Physical review letters

دوره 102 10  شماره 

صفحات  -

تاریخ انتشار 2009