INDUCED OSCILLATIONS IN AN ELECTRON-TRANSFER REACTION IN THE PRESENCEOF A BICHROMATIC ELECTROMAGNETIC-FIELD

The effect of a bi-(multi-)chromatic electromagnetic field on electron transfer dynamics in a polar solvent is examined. Whereas the electro n population dynamics is characterized by simple exponential decay in the presence of a monochromatic field, a bichromatic field gives rise to large induced coherent oscillations-in electronic density between t he reactant and product states; This oscillation is driven indefinitel y by the applied field despite the strongly dissipative environment. T he dependence of the dynamics on the reaction heat and the laser field properties is explored using an analytical expression derived within the noninteracting blip approximation. The oscillations depend on the held properties: both cosinelike and more complicated behavior can be obtained. For a trichromatic driving force, aperiodic (chaotic) oscill ations are found. Ideal conditions and possibly appropriate chemical s ystems for the experimental verification of this phenomenon are discus sed. (C) 1996 American Institute of Physics.