Electron-phonon coupling and electron self-energy in electron-doped graphene: calculation of angular resolved photoemission spectra

Abstract

We obtain analytical expressions for the electron self-energy and the electron-phonon coupling in electron-doped graphene using electron-phonon matrix elements extracted from density functional theory simulations. From the electron self-energies we calculate angle resolved photoemission spectra. We demonstrate that the measured kink at $\approx -0.2$ eV from the Fermi level is actually composed of two features, one at $\approx -0.195$ eV due to the twofold degenerate E${}_{2g}$ mode, and a second one at $\approx -0.16$ eV due to the A${}_1^{{}^{\prime }}$ mode. The electron-phonon coupling extracted from the kink observed in ARPES experiments is roughly a factor of 5.5 larger than the calculated one. This disagreement can only be partially reconciled by the inclusion of resolution effects. Indeed we show that a finite resolution increases the apparent electron-phonon coupling by underestimating the renormalization of the electron velocity at energies larger than the kinks positions. The discrepancy between theory and experiments is thus reduced to a factor of $\approx$ 2.2. From the linewidth of the calculated ARPES spectra we obtain the electron relaxation time. A comparison with available experimental data in graphene shows that the electron relaxation time detected in ARPES is almost two orders of magnitudes smaller than what measured by other experimental techniques.

9 pages, 7 figures, see also Matteo Calandra and Francesco Mauri, arXiv:0707.1492

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Cited by in corpus (18)

• Substrate-induced band gap opening in epitaxial graphene
• The Role of Electron-electron Interactions in Graphene ARPES Spectra
• Ab initio GW many-body effects in graphene
• On the universal AC optical background in graphene
• Theory of resonant multiphonon Raman scattering in graphene
• Characterization of graphene through anisotropy of constant-energy maps in angle-resolved photoemission
• Interplay of Coulomb and electron-phonon interactions in graphene
• Density-Functional Theory of Graphene Sheets
• The quasiparticle spectral function in doped graphene
• First-Principles Study of Electron Linewidths in Graphene
• Boundary problems for Dirac electrons and edge-assisted Raman scattering in graphene
• Kohn anomaly and interplay of electron-electron and electron-phonon interactions in epitaxial graphene
• Van Hove Singularity and Apparent Anisotropy in the Electron-Phonon Interaction in Graphene
• Electron-Phonon Interactions for Optical Phonon Modes in Few-Layer Graphene
• Effect of electron-electron interaction on the Fermi surface topology of doped graphene
• Chirality dependent frequency shift of radial breathing mode in metallic carbon nanotubes
• Vertex renormalization in dc conductivity of doped chiral graphene
• High resolution angle resolved photoemission studies on quasi-particle dynamics in graphite