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Structures and spectra of gold nanoclusters and quantum dot molecules

  • R. N. Barnett
  • C. L. Cleveland
  • H. Häkkinen
  • W. D. Luedtke
  • C. Yannouleas
  • U. Landman
Conference paper

Abstract

Size-evolutions of structural and spectral properties in two types of finite systems are discussed. First we focus on energetics and structures of gold clusters, particularly Au N in the 40 ≲ N ≲ 200 range exhibiting a discrete sequence of optimal clusters with a decahedral structural motif, and on the electronic structure of bare and methyl-thiol passivated Au38 clusters. Subsequently, bonding and spectra of quanturn dot molecules (QDM’s) are investigated, using a single-particle two-center oscillator model and the local-spin-density (LSD) method, for a broad range of interdot distances and coupling strengths. A molecular orbital classification of the QDM states correlates between the united-dot and separated-dots limits. LSD addition energies and spin polarization patterns for QDM’s in the entire coupling range are analyzed, guiding the construction of a constant interaction model. A generalization of the non-interacting-electrons Darwin—Fock model to QDM’s is presented. Wigner crystallization of the electrons leading to formation of Wigner supermolecules is explored in both the field-free case and with a magnetic field using a spin-andspace unrestricted Hartree—Fock Method.

PACS

36.40.Cg Electronic and magnetic properties of clusters 73.20.Dx Electron states in low-dimensional structures (superlattices, quantum well structures and multilayers) 

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Copyright information

© Springer-Verlag Italia 1999

Authors and Affiliations

  • R. N. Barnett
    • 1
  • C. L. Cleveland
    • 1
  • H. Häkkinen
    • 1
  • W. D. Luedtke
    • 1
  • C. Yannouleas
    • 1
  • U. Landman
    • 1
  1. 1.School of Physics, Georgia:Institute of TechnologyAtlantaUSA

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