Control of quantum interference in single-molecule junctions via Jahn-Teller distortion

Abstract

Quantum interference offers a unique opportunity to tune the charge transport through molecular devices and materials at the phase-coherent scale. Herein, we propose a direct way to suppress interference between two transmission paths in a meta-connected benzene ring by blocking a particular transmission path using Jahn-Teller distortion. By modification of two hydroxyls to introduce intramolecular hydrogen bonds, the conductance of single-molecule junctions with the meta-connected benzene ring is enhanced by ∼45 times and the transition from through-bond to through-space transport was observed from the flicker noise analysis. The significant difference in the charge transport originated from blocking of the transmission path due to Jahn-Teller distortion of both the electronic and the configurational structure of the benzene ring, leading to the disappearance of the destructive quantum interference feature in both experimental and theoretical results. Our findings may offer a new strategy for controlling quantum interference in future molecular devices and materials. Room-temperature quantum interference in charge transport through single-molecule junctions has attracted broad attention. Here, Chen et al. demonstrate a strategy to control quantum interference in single-molecule junctions via the Jahn-Teller distortion effect introduced by intramolecular hydrogen bonds.