title: Quantum well behavior without confining barrier observed via dynamically screened photon field.
abstract: Angle-resolved photoemission spectra from Na adlayers on Al(111) reveal features which behave like quantum well resonances although the substrate provides no confining barrier. These features are observed in a narrow photon energy range where overlayer collective excitations cause resonant enhancement of the photoemission intensity. The quantum well behavior is shown to be due to surface resonances of the Na/Al system. The resonances are observable using photoemission because of spatial confinement and dynamical enhancement of the local electric field within the Na films.
authors.affiliation: Fritz-Haber Institut der Max-Planck Gesellschaft, 14195 Berlin, Germany.
authors.forename: S R
authors.initials: SR
authors.lastname: Barman
authors.forename: P
authors.initials: P
authors.lastname: Häberle
authors.forename: K
authors.initials: K
authors.lastname: Horn
authors.forename: J A
authors.initials: JA
authors.lastname: Maytorena
authors.forename: A
authors.initials: A
authors.lastname: Liebsch