QUANTUM CONTROL OF MOLECULAR-DYNAMICS - THE STRONG RESPONSE REGIME

We consider the quantum control of molecular dynamics in the strong re sponse regime. The method used is based on a formulation in Liouville space and is valid for both the weak and strong response regimes. Seve ral previous examples using this formulation in the weak response regi me have shown that it is possible to overcome the natural tendency of wave packets to delocalize as they evolve on Bom-Oppenheimer potential surfaces. In this work we demonstrate that the weak field solutions f or the optimal electric field can be surprisingly robust, in the sense that, by increasing their intensity without altering their form, they can be extended well beyond the first-order, perturbative limit to th e regime in which significant population transfer occurs, while retain ing a high deg-ree of control. Further, since the weak field solutions are robust with respect to field strength, they can be used as initia l guesses in a procedure to find locally optimal strong response solut ions using an iterative search scheme. As a numerical application of t he theory, we demonstrate the control of the vibrational dynamics of n uclear wave packets on an electronically excited state of I-2.