Dresden 2011 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 21: TR: Nanoelectronics III - Molecular Electronics 2

TT 21.5: Talk

Tuesday, March 15, 2011, 11:30–11:45, HSZ 301

Conformational changes in biphenyl under applied voltage — •Lars Kecke and Joachim Ankerhold — Institut für theoretische Physik, Universität Ulm

The usual way to calculate the transmission of a molecule is to calculate the transmission matrix of an isolated molecule and then to add the leads. We show that, especially in case of molecules with intrinsic switching probabilities, this procedure leads to massively incorrect conductivities. We have used a Born-Oppenheimer-like master-equation approach to calculate the energy profile of the torsional degree of freedom in a molecule of biphenyl in the presence of two electrodes and found the torsional angle snapping from a roughly 45-degree position at low voltage to zero, accompied by a quantization of current, in a pattern reminiscent of Coulomb diamonds.