Optimal control by computer
The use of computer simulations studying how laser light can control the behaviour of atoms and molecules is reviewed. A variety of control schemes have been developed and we focus on three commonly used approaches: optimal control, local control and strong-field control. An overview is given of the types of control that can be achieved of interest to chemists, namely molecular alignment and orientation, isomerisation and bond breaking and forming. The calculations are very computer intensive and results from both exact solutions to the time-dependent Schrödinger equation and approximate solutions using the commonly employed trajectory surface hopping approach are covered. Of particular interest is the recent work using strong-field control, which promises to be more general and powerful than approaches based on weak-fields that do not perturb the molecular potential energy surfaces.