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

By M. Calandra, F. Mauri. 2007

136 citations recorded by the source corpus.

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 (ARPES). We demonstrate that the measured kink at $\ensuremath{\approx}\ensuremath{-}0.2\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ from the Fermi level is actually composed of two features, one at $\ensuremath{\approx}\ensuremath{-}0.195\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ due to the twofold-degenerate ${E}_{2g}$ mode, and a second one at $\ensuremath{\approx}\ensuremath{-}0.16\phantom{\rule{0.3em}{0ex}}\mathrm{eV}$ due to the ${A}_{1}^{\ensuremath{'}}$ 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 be only 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 kink positions. The discrepancy between theory and experiments is thus reduced to a factor of $\ensuremath{\approx}2.5$. From the linewidth of the calculated ARPES 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 that measured by other experimental techniques.

Subfields: Atomic and Molecular Physics, and Optics, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/cf364e4d55498e194c5fdf52861da95c61cc1d9e

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In Atomic and Molecular Physics, and Optics

In Materials Chemistry

Citations in the corpus

Electron-phonon interactions from first principles (2016, result): “Calandra and Mauri performed a combined ab initio/analytical study of the effects of the electron-phonon interaction on the electron bands of graphene and obtained very similar results [290].”
Electronic transport in two-dimensional graphene (2010, background): “…of the electronelectron and electron-phonon contribution to the quasiparticle self-energy was studied by several groups (Barlas et al., 2007; Calandra and Mauri, 2007; Carbotte et al., 2010; Hwang and Das Sarma, 2008; Hwang et al., 2007c,d; Park et al., 2007, 2009; Polini et al., 2007,…”