Berlin 2012 – scientific programme
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TT: Fachverband Tiefe Temperaturen
TT 44: Transport: Nanoelectronics III - Molecular Electronics 2
TT 44.7: Talk
Thursday, March 29, 2012, 16:45–17:00, BH 334
Quantum Interference Effects in Single-Molecule Junctions — •Stefan Ballmann1, Rainer Härtle2, Pedro Brana-Coto2, Michael Thoss2, and Heiko B. Weber1 — 1Lehrstuhl für Angewandte Physik, Universität Erlangen-Nürnberg, Germany — 2Institut für Theoretische Festkörperphysik, Universität Erlangen-Nürnberg, Germany
We analyze quantum interference effects in single-molecule junctions both experimentally and theoretically by means of the mechanically controlled break junction technique, density-functional theory and a non-equilibrium Green’s function approach. Interference occurs as a suppression of the current level, when quasi-degenerate electronic states contribute
to transport. Such levels are quite common in many
molecules used for single-molecule junctions. However, such destructive interference can be lifted by coupling
the electron system to vibrations, resulting in an enhancement of the current [1]. We demonstrate that this effect is dominant in single-molecule junctions by analyzing temperature dependent IV characteristics.
R. Härtle, M. Butzin, O. Rubio-Pons, M. Thoss, Phys. Rev. Lett. 107, 046802 (2011).