Experimental Evidence for Quantum Interference and Vibrationally Induced Decoherence in Single-Molecule Junctions

Stefan Ballmann, Rainer Härtle, Pedro B. Coto, Marcel Mayor, Mark Elbing, Martin R. Bryce, Michael Thoss, Heiko B. Weber

Published 2012-03-19Version 1

We analyze quantum interference and decoherence effects in single-molecule junctions both experimentally and theoretically by means of the mechanically controlled break junction technique and density-functional theory. We consider the case where interference is provided by overlapping quasi-degenerate states. Decoherence mechanisms arising from the electronic-vibrational coupling strongly affect the electrical current flowing through a single-molecule contact and can be controlled by temperature variation. Our findings underline the all-important relevance of vibrations for understanding charge transport through molecular junctions.