Symmetry fingerprints of a benzene single-electron transistor: Interplay between Coulomb interaction and orbital symmetry

The interplay between Coulomb interaction and orbital symmetry produces specific transport characteristics in molecular single electron transistors (SETs) 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.