Ab initio GW many-body effects in graphene

Abstract

We present an {\it ab initio} many-body GW calculation of the self-energy, the quasiparticle band plot and the spectral functions in free-standing undoped graphene. With respect to other approaches, we numerically take into account the full ionic and electronic structure of real graphene and we introduce electron-electron interaction and correlation effects from first principles. Both non-hermitian and also dynamical components of the self-energy are fully taken into account. With respect to DFT-LDA, the Fermi velocity is substantially renormalized and raised by a 17%, in better agreement with magnetotransport experiments. Furthermore, close to the Dirac point the linear dispersion is modified by the presence of a kink, as observed in ARPES experiments. Our calculations show that the kink is due to low-energy $\pi \to {\pi }^{\ast }$ single-particle excitations and to the $\pi$ plasmon. Finally, the GW self-energy does not open the band gap.

5 pages, 4 figures, 1 table

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Cited by in corpus (3)

• Excitonic Effects on the Optical Response of Graphene and Bilayer Graphene
• First-Principles Study of Electron Linewidths in Graphene
• Spin-resolved Quantum Interference in Graphene