Current-Driven Conformational Changes, Charging and Negative Differential Resistance in Molecular Wires

We introduce a theoretical approach based on scattering theory and total energy methods that treats transport non-linearities, conformational changes and charging effects in molecular wires in a unified way. We apply this approach to molecular wires consisting of chain molecules with different electronic and structural properties bonded to metal contacts. We show that non-linear transport in all of these systems can be understood in terms of a single physical mechanism and predict that negative differential resistance at high bias should be a generic property of such molecular wires.