title: Kohn anomalies and electron-phonon interactions in graphite.
abstract: We demonstrate that graphite phonon dispersions have two Kohn anomalies at the Gamma-E(2g) and K-A'1 modes. The anomalies are revealed by two sharp kinks. By an exact analytic derivation, we show that the slope of these kinks is proportional to the square of the electron-phonon coupling (EPC). Thus, we can directly measure the EPC from the experimental dispersions. The Gamma-E(2g) and K-A'1 EPCs are particularly large, while they are negligible for all the other modes at Gamma and K.
authors.affiliation: Cambridge University, Engineering Department, Trumpington Street, Cambridge CB2 1PZ, United Kingdom.
authors.forename: S
authors.initials: S
authors.lastname: Piscanec
authors.forename: M
authors.initials: M
authors.lastname: Lazzeri
authors.forename: Francesco
authors.initials: F
authors.lastname: Mauri
authors.forename: A C
authors.initials: AC
authors.lastname: Ferrari
authors.forename: J
authors.initials: J
authors.lastname: Robertson