Quantum interference through gated single-molecule junctions

TL;DR

This paper presents a method to predict quantum interference effects in single-molecule junctions using Green functions and tight-binding models, demonstrated with a gated benzene molecule to analyze antiresonances.

Contribution

It introduces graphical rules derived from Green function properties to assess quantum interference in molecular junctions, enabling practical predictions for different connection topologies.

Findings

Graphical rules for predicting antiresonances in molecular junctions

Tunable quantum interference effects in a gated benzene molecule

Method applicable to various molecular connection configurations

Abstract

We discuss the general form of the transmission spectrum through a molec- ular junction in terms of the Green function of the isolated molecule. By introducing a tight binding method, we are able to translate the Green func- tion properties into practical graphical rules for assessing beforehand the possible existence of antiresonances in an energy range for a given choice of connecting sites. The analysis is exemplified with a benzene molecule under a hypothetical local gate, which allows one to continuously tune the on-site energy of single atoms, for various connection topologies and gate positions.