Regensburg 2013 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 4: Transport: Quantum Dots, Wires, Point Contacts 1 (jointly with HL and TT)
O 4.6: Vortrag
Montag, 11. März 2013, 10:45–11:00, H20
Iterative summation of path integrals for nonequilibrium molecular quantum transport — Roland Huetzen1, •Stephan Weiss1,2, Michael Thorwart3, and Reinhold Egger1 — 1Heinrich-Heine Universität Düsseldorf, Universitätsstr.1, 40225 Düsseldorf — 2Universität Duisburg-Essen and CENIDE, 47048 Duisburg — 3Universität Hamburg, Jungiusstr. 9, 20355 Hamburg
We formulate and apply a nonperturbative numerical approach
to the nonequilibrium current, I(V), through a voltage-biased
molecular conductor. We focus on a single electronic
level coupled to an unequilibrated vibration mode (Anderson-Holstein model),
which can be mapped to an effective three-state problem. Performing an
iterative summation of real-time path integral (ISPI) expressions,
we accurately reproduce known analytical results in three different limits.
We then study the crossover regime between those limits and show that the
Franck-Condon blockade persists in the quantum-coherent low-temperature
limit, with a nonequilibrium smearing of step features in the IV curve.
[1] S. Weiss, J. Eckel, M. Thorwart, and R. Egger, Phys. Rev. B 77, 195316 (2008).
R. Hützen, S. Weiss, M. Thorwart, and R. Egger, Phys. Rev. B 85, 121408 (2012).