Title

Phonon-Induced Surface Charge Density Oscillations In Quantum Wells: A First-Principles Study Of The (2 × 2)-K Overlayer On Be(0001)

Abstract

Density functional perturbation theory has been applied to study the surface vibrations of (2 × 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 λ and M for the alkali SV and L modes. Surprisingly, at the M 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 × 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. © 2011 American Chemical Society.

Publication Date

6-30-2011

Publication Title

Journal of Physical Chemistry A

Volume

115

Issue

25

Number of Pages

7242-7248

Document Type

Article

Personal Identifier

scopus

DOI Link

https://doi.org/10.1021/jp200373h

Socpus ID

79959535199 (Scopus)

Source API URL

https://api.elsevier.com/content/abstract/scopus_id/79959535199

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