Screening of electron-phonon coupling in graphene on Ir(111)
English
Endlich, M.[Technische Universität Illmenau, Germany]
Molina-Sanchez, Alejandro[University of Luxembourg > Faculty of Science, Technology and Communication (FSTC) > Physics and Materials Science Research Unit >]
Wirtz, Ludger[urg, Physics and Material Sciences Research Unit / CNRS UMR 8520, IEMN, France]
[en] The phonon dispersion of graphene on Ir(111) has been determined by means of angle-resolved inelastic electron scattering and density functional calculations. Kohn anomalies of the highest optical-phonon branches are observed at the ¯ and ¯K point of the surface Brillouin zone. At ¯K the Kohn anomaly is weaker than observed for pristine graphene and graphite. This observation is rationalized in terms of a decrease of the electron-phonon coupling due to screening of graphene electron correlations by the metal substrate.