Antiabsorption resonances in infrared reflectance spectroscopy of alkali-Cu(111) adsorbate systems: Is the ground state a surface charge density wave condensate?

F. M. Hoffmann; B. N. J. Persson; W. Walter; D. A. King; C. J. Hirschmugl; G. P. Williams

doi:10.1103/PhysRevLett.72.1256

Antiabsorption resonances in infrared reflectance spectroscopy of alkali-Cu(111) adsorbate systems: Is the ground state a surface charge density wave condensate?

F. M. Hoffmann, B. N. J. Persson, W. Walter, D. A. King, C. J. Hirschmugl, and G. P. Williams

Phys. Rev. Lett. 72, 1256 – Published 21 February 1994

Abstract

We have observed antiabsorption resonances when alkali metals are adsorbed on Cu(111). The resonances occur at ħ $ω_{0}$ ≊0.1 eV and cannot be attributed to phonon modes. We show that the experimental data can be consistently explained by attributing the resonances to vibrations, parallel to the surface, of a pinned surface charge density wave (CDW). We estimate the CDW effective mass to be $m^{*}$ ≊500 $m_{e}$ per electron in the condensate.

Received 18 October 1993

DOI:https://doi.org/10.1103/PhysRevLett.72.1256

Authors & Affiliations

F. M. Hoffmann, B. N. J. Persson, W. Walter, D. A. King, C. J. Hirschmugl, and G. P. Williams

Exxon Research and Engineering, Annandale, New Jersey 08801
Institut für Festköperforschung, Forschungszentrum Jülich, D-52425 Jülich, Germany
Department of Chemistry, University of Cambridge, Cambridge CB2 1EW, United Kingdom
Brookhaven National Laboratories, Upton, New York 11973