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arXiv · 1101.3892

Dynamical symmetry breaking in vibration-assisted transport through nanostructures

Abdullah Yar·Andrea Donarini·Sonja Koller·Milena Grifoni
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Abstract

A theoretical model of a single molecule coupled to many vibronic modes is presented. At low energies, transport is dominated by electron-vibron processes where transfer of an electron through the dot is accompanied by the excitation/emission of quanta (vibrons). Because the frequency of the $n$th mode is taken as an $n$th multiple of the frequency of the fundamental mode, several energetically degenerate or quasi-degenerate vibronic configurations can contribute to transport. We investigate the consequences of strong electron-vibron coupling in a fully \emph{symmetric} set-up. Several striking features are predicted. In particular, a gate-asymmetry and pronounced negative differential conductance features are observed. We attribute these features to the presence of slow channels originating from the interplay of Franck-Condon suppression of transport channels and spin/orbital degeneracies.

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Abdullah Yar, Andrea Donarini, Sonja Koller, Milena Grifoni. 2011-01-20. Dynamical symmetry breaking in vibration-assisted transport through nanostructures. https://doi.org/10.1103/physrevb.84.115432

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