Laser control schemes for molecular switches

Molecular switches are discussed as promising nanoscale devices for various applications including data storage and information processing. For this purpose a high controllability of the complete switching process is desirable. We propose to use shaped femtosecond laser pulses to initiate and control a fast and efficient switching process mediated by conical intersections. We focus on photoreactions of bistable molecules in which the ring opening of 1,3-cyclohexadiene constitutes the key activity. The investigations of control schemes for this type of reactions are carried out in a model based on ab initio and quantum dynamical calculations of the ring-opening reaction of cyclohexadiene. By defining an intermediate target, we can achieve product control with optimized laser pulses in this model.