A charge-dipole interaction model for the frequency-dependent polarizability of silver clusters

A. Mayer*, A. L. Gonzalez, C. M. Aikens, G. C. Schatz

*Corresponding author for this work

Research output: Contribution to journalArticle

17 Scopus citations

Abstract

We present a charge-dipole interaction model for the calculation of the frequency-dependent polarizability of silver clusters. The model relies on the representation of silver atoms by both a net electric charge and a dipole. Time variations of the atomic charges are related to the currents that flow through the bonds of the structures considered and the atomic charges and dipoles are eventually determined from the application of a least-action principle. After a generalization that enables the bonds of the bulk and surface atoms to have specific resistances, the model is parameterized on data obtained by the time-dependent density functional theory for tetrahedral Ag20, Ag84 and Ag120 clusters. We then study the polarization properties of dimers of silver clusters. We compare in particular the polarizability of the dimers with that of the isolated clusters, for a range of gap distances and frequencies. We also consider the field enhancements one can achieve with these systems. The results are in good agreement with reference data and enable an extension of these data to a wider range of situations. They show that significant field enhancements are achieved at frequencies associated with resonant polarization along the axis of the dimer.

Original languageEnglish (US)
Article number195204
JournalNanotechnology
Volume20
Issue number19
DOIs
StatePublished - May 20 2009

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Mechanics of Materials
  • Mechanical Engineering
  • Electrical and Electronic Engineering

Fingerprint Dive into the research topics of 'A charge-dipole interaction model for the frequency-dependent polarizability of silver clusters'. Together they form a unique fingerprint.

  • Cite this