Optimal control of molecular electronics by femtosecond laser pulses

TL;DR

This paper develops a quantum control framework using femtosecond laser pulses to precisely manipulate electron currents in molecular wires, enabling high-speed optical switching in molecular electronic devices.

Contribution

It introduces a novel optimal control method for designing laser pulses to control electron transport in molecular wires within a quantum master equation framework.

Findings

Laser pulses can switch current on and off in molecular wires.

The control scheme allows arbitrary current patterns over time.

The formalism is applicable to tight-binding models of molecular wires.

Abstract

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. For a tight-binding approximation of the wire we show how to compute the laser pulses to switch the current through the wire on and off. With this approach the desired pattern of the current in time can be chosen in an almost arbitrary fashion.