Title

Acoustic surface plasmon on Cu(111)

Abstract

Contrary to previous reports we show that the acoustic surface plasmon (ASP) exists also at noble-metal surfaces, thus demonstrating the generality of this phenomenon in the presence of partially filled Shockley surface states. Angle-resolved high-resolution electron energy loss spectroscopy measurements and calculations of the surface loss function indicate that for Cu(111) the ASP is a sharp feature up to a loss energy of about 0.4 eV. The dispersion is indeed linear (acoustic) with a slope (sound velocity) of (4.33 +/- 0.33) eV angstrom in good agreement with recent theoretical predictions. The ASP can play important roles down to the meV regime, precluded to ordinary surface plasmons, for electron, phonon and adsorbate dynamics, as well as chemical reactions and advanced microscopies. Copyright (C) EPLA, 2010

Publication Date

7-5-2010

Journal Title

Epl

Publisher

EPL ASSOCIATION, EUROPEAN PHYSICAL SOCIETY

Digital Object Identifier (DOI)

10.1209/0295-5075/90/57006

Document Type

Article

Rights

Copyright EPLA, 2010