Coherent control in the continuum: autoionization of Xe

We explore, by time-dependent MQDT calculations, the potential for coherent control of autoionization using phase-shaped optical pulses. We investigate the effect of step-like spectral phase modulation on the autoionization dynamics of Rydberg wave packets in the Xe atom. It is found that a single step in the spectral phase has a substantial effect on the branching ratio, if the position of the step corresponds to a resonance in the Rydberg system. These effects are enhanced if the optical pulse is engineered to have multiple steps that reflect the periodicity inherent in Rydberg systems. Further calculations indicate that, to a large extent, the effects of phase manipulations are additive and independent. We also compare this new approach with approaches based on sequences of identical coherent optical pulses. The two methods are complementary, and we suggest that in the future they may be combined.