Quantum optimal control of unbounded molecular dynamics: Application to NaI predissociation

In order to achieve optimal control of unbounded molecular dynamics, we develop an algorithm to deal with a spatially delocalized final condition of homogeneous pulse design equations that are derived from a typical optimal control procedure. We introduce a quasiprojector to specify a spatially delocalized physical objective, while we store wave packet components that spread beyond the grid region in memory. The quasiprojector, which can explicitly identify target products in photodissociation and bimolecular reactions, is a weighted sum of projectors, whose weight function is constant outside the grid region. This algorithm, combined with an efficient iteration method, is applied to the control of NaI predissociation with the aim of obtaining a high dissociation probability within one cycle of nuclear vibration. We discuss how the control mechanisms are changed depending on the potential coupling strengths and restriction imposed on the optical interaction region. The effects of molecular orientation on a control pathway are also examined using a two-orientation model with the assumption of a frozen rotational wave packet. (C) 2002 American Institute of Physics.