Regensburg 2013 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 58: Poster Session Transport & Matter at Low Temperature
TT 58.20: Poster
Thursday, March 14, 2013, 15:00–19:00, Poster D
Model study of vibrationally dependent electron-electron interactions in single-molecule junctions — •André Erpenbeck1, Rainer Härtle1,2, Michel Bockstedte1, and Michael Thoss1 — 1Institut für Theoretische Physik, Friedrich-Alexander-Universität Erlangen- Nürnberg, Staudtstr. 7/B2, D-91058 Erlangen, Germany — 2Department of Physics, Columbia University, 538 W. 120th St., New York, NY 10027, USA
In a single molecule junction, the interaction of the electrons with the vibrational degrees of freedom gives rise to direct electronic-vibrational coupling, but results also in vibrationally dependent electron-electron interactions. We derive a general, reduced model that incorporates vibrationally dependent electron-electron interactions and show that it leads to an effective electronic-vibrational coupling, which depends on the population of the electronic states of the molecular bridge. Employing a Born-Markov master equation approach, the influence of the interactions on the transport characteristics is analyzed. In particular, we show that vibrationally dependent electron-electron interactions may result in regimes of purely electronic transport, negative differential resistance, a significant decrease of the vibrational excitation as well as characteristic asymmetries in the gate-voltage dependence of the conductance properties of a molecular contact.