[en] We compute the electron-phonon coupling (EPC) of selected phonon modes in graphene and graphite using various ab initio methods. The inclusion of nonlocal exchange-correlation effects within the GW approach strongly renormalizes the square EPC of the A(1)' K mode by almost 80% with respect to density-functional theory in the LDA and GGA approximations. Within GW, the phonon slope of the A(1)' K mode is almost two times larger than in GGA and LDA, in agreement with phonon dispersions from inelastic x-ray scattering and Raman spectroscopy. The hybrid B3LYP functional overestimates the EPC at K by about 30%. Within the Hartree-Fock approximation, the graphene structure displays an instability under a distortion following the A(1)' 'phonon at K.
Disciplines :
Physics
Author, co-author :
Lazzeri, Michele; IMPMC, Universités Paris 6 et 7, IPGP, CNRS
Attaccalite, Claudio; Universidad del Pais Vasco > 2Unidad de Fisica de Materiales, European Theoretical Spectroscopy Facility (ETSF)
Wirtz, Ludger ; CNRS UMR 8520 > Institute for Electronics, Microelectronics, and Nanotechnology
Mauri, Francesco; IMPMC, Universités Paris 6 et 7, IPGP, CNRS
Language :
English
Title :
Impact of the electron-electron correlation on phonon dispersion: Failure of LDA and GGA DFT functionals in graphene and graphite