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TT: Fachverband Tiefe Temperaturen

TT 16: TR: Nanoelectronics III - Molecular Electronics 1

TT 16.4: Talk

Monday, March 14, 2011, 19:00–19:15, HSZ 03

Electrostatic Potential Profiles and Current Voltage Characteristics of Molecular Wires: Effects of Dephasing — •Thomas Stegmann, Matías Zilly, and Dietrich E. Wolf — Department of Physics and CeNIDE, University of Duisburg-Essen, D-47048 Duisburg, Germany

The transport properties of molecular wires are studied using a tight-binding Hamiltonian and non-equilibrium Green’s function (NEGF) method. We have developed a statistical model for the effects of dephasing [1], that assumes coherent transport between a distribution of completely phase randomizing regions. Recently, this model has been applied successfully on the conduction of DNA molecules in zero-bias approximation [2].

Here we present the extension of our model to finite bias requiring to take Coulomb interactions into account. This is done by means of the Hartree approximation where a self-consistent solution of both Poisson’s equation and NEGF formalism has to be calculated. As a first application electrostatic potential profiles and current voltage characteristics of linear chains are shown. We demonstrate that the current depends sensitively on whether energy relaxation processes take place in the dephasing regions or not.
M. Zilly, O. Ujsághy and D. E. Wolf, Eur. Phys. B, 68:237 (2009)
M. Zilly, O. Ujsághy and D. E. Wolf, Phys. Rev. B, 82:125125 (2010)