Berlin 2005 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 8: Posters Transport
TT 8.31: Poster
Freitag, 4. März 2005, 14:00–18:00, Poster TU C
A perturbative expansion of shot noise in quantum dots and molecules — •Matthias Hettler1, Jasmin Aghassi1,2, Axel Thielmann1, Jürgen König3, and Gerd Schön1,2 — 1Forschungszentrum Karlsruhe, Institut für Nanotechnologie,76021 Karlsruhe, Germany — 2Institut für Theoretische Festkörperphysik , Universität Karlsruhe, 76128 Karlsruhe, Germany — 3Institut für Theoretische Physik III, Ruhr-Universität Bochum, 44780 Bochum, Germany
We study current and shot noise in perturbation theory in the coupling of a mesoscopic object (e.g. quantum dot or molecule) to metallic electrodes. We explicitly account for the electronic interactions and the resulting many-body states of the molecule/quantum dots, and allow for relaxation of the excited states. We present in some detail the diagrammatic technique that allows for the computation of the noise to second order in the molecule-electrode coupling. In particular, we discuss the influence of co-tunneling processes as well as the effect of intermolecular (interdot) couplings and relaxation on the shot noise. Furthermore, we find the Fano factor to be very sensitive to the tunnel-coupling strength, which may serve as a spectroscopic tool for the various coupling strengths.