Electron-Phonon Coupling and Large Intrinsic Bandgap in Highly-Screened Graphene

ORAL

Abstract

The electron-electron and electron-phonon interactions are two of the most fundamental interactions in many-body physics, leading to Mott insulating behavior and superconductivity. In graphene, the pointlike Fermi surface and linear band dispersions give these interactions distinctive characteristics with respect to normal metals. Here we present data on the electron-phonon interaction in highly-screened graphene, which we have analyzed by angle-resolved photoemission spectroscopy (ARPES). In contrast with every previous ARPES study, the magnitude of our extracted electron-phonon coupling constants generally agree with theoretical predictions. We also demonstrate the presence of a 400 meV bandgap at the Dirac point in epitaxial graphene on a copper substrate. These results shed light on the nature of the electron-phonon interaction and the tunability of the Dirac quasiparticles in graphene.

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Authors

  • David Siegel

    • University of California, Berkeley / Lawrence Berkeley National Lab

  • Choongyu Hwang

    • Lawrence Berkeley National Laboratory

  • Alexei Fedorov

    • Advanced Light Source, Lawrence Berkeley National Laboratory

  • Alessandra Lanzara

    • University of California, Berkeley / Lawrence Berkeley National Lab
    • University California, Berkeley and Material Sciences Division, Lawrence Berkeley National Laboratory
    • Department of Physics, UC Berkeley; Materials Science Division, LBNL
    • Department of Physics, University of California, Berkeley, CA 94720, USA