laboratoire pierre aigrain
électronique et photonique quantiques
laboratoire pierre aigrain

Séminaire 4 Avril 2011

Francesco MAURI (Institut de Minéralogie et Physique des Milieux Condensés, UPMC)
Electron-phonon and phonon-phonon interaction in graphene : Kohn anomalies, phonon lifetimes and charge transport at high bias.

We predict and identify, in experimental data, the presence of significant Kohn anomalies in the phonon dispersion of graphite and graphene. We use these Kohn anomalies, together with the Raman and IR lifetimes and temperature-shifts, to obtain, from experiments, accurate values of the electron-phonon and phonon-phonon coupling of graphite based materials. We show that in graphene and graphite DFT is not able to correctly account for the experimentally observed electron-phonon interaction and one need to include electron-correlation effects at the GW level. The detailed knowledge of the electron-phonon and phonon-phonon interaction parameters allows us to study the origin of current saturation in graphene at high field.