Coulomb blockade effects in driven electron transport

We study numerically the influence of strong Coulomb repulsion on the current through molecular wires that are driven by external electromagnetic fields. The molecule is described by a tight-binding model whose first and last site is coupled to a respective lead. The leads are eliminated within a perturbation theory yielding a master equation for the wire. The decomposition into a Floquet basis enables an efficient treatment of the driving field. For the electronic excitations in bridged molecular wires, we find that strong Coulomb repulsion significantly sharpens resonance peaks. By contrast, Coulomb blockade has only a small influence on effects like non-adiabatic electron pumping and coherent current suppression. PACS. 05.60.Gg Quantum transport – 85.65.+h Molecular electronic devices – 72.40.+w Photoconduction and photovoltaic effects – 73.63.-b Electronic transport in mesoscopic or nanoscale materials and structures