Electron-phonon coupling at metal surfaces

Experiments dealing with electron-phonon coupling at metal surfaces are reviewed. Issues as diverse as reconstructions at surfaces, Kohn anomalies, Peierls distortions, electron transfer between adsorbate and substrate and superconductivity are addressed. We discuss the renormalization of surface phonon and electron dispersion due to electron-phonon coupling as well as the impact of the electron-phonon interaction on the lifetime of electronic excitations. It is emphasized that in many cases only the combination of analyses of vibrational and electronic structure leads to an unambiguous and comprehensive description of the surface dynamics.