title: Vibrational lifetimes of hydrogen on lead films: an ab initio molecular dynamics with electronic friction (AIMDEF) study.
abstract: Using density functional theory and Ab Initio Molecular Dynamics with Electronic Friction (AIMDEF), we study the adsorption and dissipative vibrational dynamics of hydrogen atoms chemisorbed on free-standing lead films of increasing thickness. Lead films are known for their oscillatory behaviour of certain properties with increasing thickness, e.g., energy and electron spillout change in discontinuous manner, due to quantum size effects [G. Materzanini, P. Saalfrank, and P. J. D. Lindan, Phys. Rev. B 63, 235405 (2001)]. Here, we demonstrate that oscillatory features arise also for hydrogen when chemisorbed on lead films. Besides stationary properties of the adsorbate, we concentrate on finite vibrational lifetimes of H-surface vibrations. As shown by AIMDEF, the damping via vibration-electron hole pair coupling dominates clearly over the vibration-phonon channel, in particular for high-frequency modes. Vibrational relaxation times are a characteristic function of layer thickness due to the oscillating behaviour of the embedding surface electronic density. Implications derived from AIMDEF for frictional many-atom dynamics, and physisorbed species will also be given.
authors.affiliation: Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Strasse 24-25, D-14476 Potsdam, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Saalfrank
authors.affiliation: Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, 20018 Donostia-San Sebastián, Spain.
authors.forename: J I
authors.initials: JI
authors.lastname: Juaristi
authors.affiliation: Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, 20018 Donostia-San Sebastián, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Alducin
authors.affiliation: Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, 20018 Donostia-San Sebastián, Spain.
authors.forename: M
authors.initials: M
authors.lastname: Blanco-Rey
authors.affiliation: Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, 20018 Donostia-San Sebastián, Spain.
authors.forename: R Díez
authors.initials: RD
authors.lastname: Muiño