title: Mode-selected electron-phonon coupling in superconducting Pb nanofilms determined from He atom scattering.
abstract: The electron-phonon coupling (EPC) strength for each phonon mode in superconducting Pb films is measured by inelastic helium atom scattering (IHAS). This surprising ability of IHAS relies on two facts: (a) In ultrathin metal films, the EPC range exceeds the film thickness, thus enabling IHAS to detect most film phonons, even 1 nm below the surface; (b) IHAS scattering amplitudes from single phonons are shown, by first-principle arguments, to be proportional to the respective EPC strengths. Thus IHAS is the first experiment providing mode-selected EPC strengths (mode-lambda spectroscopy).
authors.affiliation: Donostia International Physics Centre (DIPC), Paseo Manuel de Lardizàbal 4, 20018 Donostia/San Sebastian, Spain.
authors.forename: I Yu
authors.initials: IY
authors.lastname: Sklyadneva
authors.forename: G
authors.initials: G
authors.lastname: Benedek
authors.forename: E V
authors.initials: EV
authors.lastname: Chulkov
authors.forename: P M
authors.initials: PM
authors.lastname: Echenique
authors.forename: R
authors.initials: R
authors.lastname: Heid
authors.forename: K-P
authors.initials: KP
authors.lastname: Bohnen
authors.forename: J P
authors.initials: JP
authors.lastname: Toennies