Berlin 2005 – wissenschaftliches Programm
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A: Atomphysik
A 13: Poster HU 2
A 13.27: Poster
Dienstag, 8. März 2005, 08:30–18:30, Poster HU
Electronic transport through metallic clusters at surfaces — •Mario de Menech1, Ulf Saalmann1, and Martin E Garcia2 — 1MPI Physik komplexer Systeme, Nöthnitzer Str. 38, 01187 Dresden — 2Universität Gh Kassel, Theoretische Physik, Heinrich-Plett-Str.40, 34132 Kassel
The investigation of clusters at surfaces is currently a very active field of research for possible technical applications which may take advantage of their peculiar properties, different both from individual atoms and bulk solids. In particular, scanning tunnelling spectroscopy is in principle the ideal tool to obtain information on the electronic structure of these supported particles. The theoretical understanding of the features observed in the measured spectra, however, is still rather limited.
We consider noble metal clusters having up to a hundred atoms deposited on an ideal graphite surface, and calculate their electronic structure with an approximated DFT/LCAO method. Electronic transport is described within the non-equilibrium Green function formalism, which allows us to include consistently the non-linear effects due to charge redistribution at finite biases. The effects of the probe set point and the spectral density of the substrate on the differential conductance are discussed in detail, and related to the actual density of states of the supported clusters.