Tailoring current flow patterns through molecular wires using shaped optical pulses

Combining the features of molecular wires and femtosecond laser pulses gives the unique opportunity to optically switch electron currents in molecular devices with very high speed. Based on a weak-coupling approximation between wire and leads, a quantum master equation for the population dynamics and the electric current through the molecular wire has been developed, which allows for arbitrary time-dependent laser fields interacting with the wire. This formalism is combined with the theory of optimal control, leading to an innovative control of targets distributed in time in open quantum systems. For a tight-binding approximation of the molecular wire, we show how to compute the laser pulses to switch the current through the wire on and off. With this approach, the current flow pattern of the current in time can be chosen in an almost arbitrary fashion.