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

TL;DR

This study combines experimental and theoretical approaches to investigate how quantum interference and vibrationally induced decoherence influence electron transport in single-molecule junctions, highlighting the critical role of vibrations.

Contribution

It provides new experimental and theoretical insights into vibrationally induced decoherence effects on quantum interference in molecular electronics.

Findings

Vibrations significantly impact charge transport in molecular junctions.

Decoherence can be controlled by temperature variation.

Quantum interference effects are influenced by vibrational coupling.

Abstract

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.