Symmetry fingerprints of a benzene single-electron transistor

TL;DR

This paper predicts how contact configuration changes in a benzene single-electron transistor affect conductance, revealing interference effects that serve as fingerprints of molecular symmetry and contact geometry.

Contribution

It introduces a theoretical prediction of conductance suppression and negative differential conductance due to interference effects in benzene SETs based on contact configuration.

Findings

Selective conductance suppression in meta configuration

Appearance of negative differential conductance

Interference effects linked to orbital degeneracy

Abstract

The interplay between Coulomb interaction and orbital symmetry produces specific transport characteristics in molecular single electron transistors (SET) that can be considered as the fingerprints of the contacted molecule. Specifically we predict, for a benzene SET, selective conductance suppression and the appearance of negative differential conductance when changing the contacts from para to meta configuration. Both effects originate from destructive interference in transport involving states with orbital degeneracy.