Phonon-Induced Surface Charge Density Oscillations in Quantum Wells: A First-Principles Study of the (2 x 2)-K Overlayer on Be(0001)

    Authors

    V. Chis;G. Benedek

    Comments

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    Abbreviated Journal Title

    J. Phys. Chem. A

    Keywords

    ALKALI-METAL ADSORPTION; HELIUM-ATOM SCATTERING; AB-INITIO; HE-SCATTERING; NOBLE-METALS; SUPERCONDUCTIVITY; CU(111); GRAPHITE; MONOLAYER; EXPANSION; Chemistry, Physical; Physics, Atomic, Molecular & Chemical

    Abstract

    Density functional perturbation theory has been applied to study the surface vibrations of (2 x 2)-K monolayer on the Be(0001) surface. We present the full phonon dispersion curves along the high symmetry directions of the surface Brillouin zone (SBZ) together with the layer-projected phonon density of states and the phonon-induced surface charge density oscillations at (Gamma) over bar and (M) over bar for the alkali SV and L modes. Surprisingly, at the (M) over bar point, the L-phonon displacements produce a more pronounced perturbation on the surface charge density than the SV-phonon displacements. These results apparently solve the long-standing question regarding helium atom scattering (HAS) experiments performed on the similar system (2 x 2)-K on graphite, where the alkali SV phonon mode is not observed. Moreover, this result confirms the previous finding that HAS from free-electron metal surfaces probes directly the phonon-induced charge density oscillations and the related electron-phonon interaction.

    Journal Title

    Journal of Physical Chemistry A

    Volume

    115

    Issue/Number

    25

    Publication Date

    1-1-2011

    Document Type

    Article

    Language

    English

    First Page

    7242

    Last Page

    7248

    WOS Identifier

    WOS:000291895500060

    ISSN

    1089-5639

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