title: Phonon dispersion and lifetimes in MgB2.
abstract: We measure phonon dispersion and linewidth in a single crystal of MgB2 along the Gamma-A, Gamma-M, and A-L directions using inelastic x-ray scattering. We use density functional theory to compute the effect of both electron-phonon coupling and anharmonicity on the linewidth, obtaining excellent agreement with experiment. Anomalous broadening of the E(2g) phonon mode is found all along Gamma-A. The dominant contribution to the linewidth is always the electron-phonon coupling.
authors.affiliation: Laboratoire de Minéralogie-Cristallographie, case 115, 4 Place Jussieu, 75252, Paris cedex 05, France.
authors.forename: Abhay
authors.initials: A
authors.lastname: Shukla
authors.forename: Matteo
authors.initials: M
authors.lastname: Calandra
authors.forename: Matteo
authors.initials: M
authors.lastname: D'Astuto
authors.forename: Michele
authors.initials: M
authors.lastname: Lazzeri
authors.forename: Francesco
authors.initials: F
authors.lastname: Mauri
authors.forename: Christophe
authors.initials: C
authors.lastname: Bellin
authors.forename: Michael
authors.initials: M
authors.lastname: Krisch
authors.forename: J
authors.initials: J
authors.lastname: Karpinski
authors.forename: S M
authors.initials: SM
authors.lastname: Kazakov
authors.forename: J
authors.initials: J
authors.lastname: Jun
authors.forename: D
authors.initials: D
authors.lastname: Daghero
authors.forename: K
authors.initials: K
authors.lastname: Parlinski