title: Measurement of anomalous phonon dispersion of CaFe2As2 single crystals using inelastic neutron scattering.
abstract: We measured phonon dispersions of CaFe2As2 using inelastic neutron scattering and compared our results to predictions of density functional theory in the local density approximation. The calculation gives correct frequencies of most phonons if the experimental crystal structure is used, except observed linewidths/frequencies of certain modes were larger/softer than predicted. Strong temperature dependence of some phonons near the structural phase transition near 172 K may indicate strong electron-phonon coupling and/or anharmonicity, which may be important for superconductivity.
authors.affiliation: Juelich Centre for Neutron Science, IFF, Forschungszentrum Juelich, Outstation at FRM II, Lichtenbergstreet 1, D-85747 Garching, Germany.
authors.forename: R
authors.initials: R
authors.lastname: Mittal
authors.forename: L
authors.initials: L
authors.lastname: Pintschovius
authors.forename: D
authors.initials: D
authors.lastname: Lamago
authors.forename: R
authors.initials: R
authors.lastname: Heid
authors.forename: K-P
authors.initials: KP
authors.lastname: Bohnen
authors.forename: D
authors.initials: D
authors.lastname: Reznik
authors.forename: S L
authors.initials: SL
authors.lastname: Chaplot
authors.forename: Y
authors.initials: Y
authors.lastname: Su
authors.forename: N
authors.initials: N
authors.lastname: Kumar
authors.forename: S K
authors.initials: SK
authors.lastname: Dhar
authors.forename: A
authors.initials: A
authors.lastname: Thamizhavel
authors.forename: Th
authors.initials: T
authors.lastname: Brueckel