Regensburg 2007 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 6: Nanoelectronics III - Molecular Electronics

TT 6.7: Talk

Monday, March 26, 2007, 15:45–16:00, H19

Coulomb repulsion effects in driven electron transport through molecules — •Franz J. Kaiser, Peter Hänggi, and Sigmund Kohler — Institut für Physik, Universität Augsburg, 86135 Augsburg

We investigate the influence of strong Coulomb repulsion on the current through molecular wires. The molecule is described by a tight-binding model whose first and last site is coupled to a respective lead. The leads are eliminated within a perturbation theory yielding a master equation for the wire. In the non-driven case, we explore the transport properties of a bridged molecular wire, where the current decays exponentially as a function of the wire length [1]. For studying conductors driven by external electromagnetic fields, we decompose the reduced density operator into a Floquet basis. This enables an efficient treatment of the time-dependent transport problem. For the electronic excitations in bridged molecular wires, we find that strong Coulomb repulsion significantly sharpens resonance peaks which broaden again with increasing temperature [2].

[1] F.J. Kaiser, M. Strass, S. Kohler, and P.Hänggi, Chem. Phys. 322, 193 (2006)

[2] F.J. Kaiser, P.Hänggi, and S. Kohler, Eur. Phys. J. (in press); cond-mat/0606457