Single Molecule Quantum Transport in the Presence of Built-in Electric Fields - a Design Principle?

Controlling transport in single molecules remains a major challenge, in part due to the difficulties of predicting the electronic structure of a molecule when supported in a metallic nanostructure. Here we discuss the possibility of using molecular dipole moments as built-in electric fields in single molecules to shift the energy level alignment and therefore tailor quantum transport. On the basis of advanced statistical analysis of experimental data from a set of model molecules, we are able to differentiate even rather small differences in the conductance, which enables us to investigate whether built-in electric fields are a useful approach to tailor the interfacial electronic structure in single molecule junctions.