Coherent Elastic Transport Contribution to Currents through Ordered DNA Molecular Junctions

The recently reported experimental control of the connectivity between double-stranded DNA and the electrodes in a junction is proposed as a tool or characterizing the mechanisms of charge transport through DNA. In particular, sensitivity of the current-voltage curve to the connectivity strategy can probe the contribution of coherent elastic charge transport to the current through DNA junctions. Landauer transport calculations show that for ordered long DNA sequences, the efficiency of the coherent transport increases by several orders of magnitude, and the calculated currents associated with the purely coherent transport mechanism become as high as currents measured in transport experiments on DNA junctions. The possibility that coherent transport through long ordered sequences may become as efficient as incoherent transport is raised.