Precise manipulation of Rydberg wave packets

The creation and control of mesoscopic, very-high-$n$ ($n \sim 300$) near-circular Rydberg wave packets, whose quantum coherence can be maintained over hundreds of classical orbital periods, is described. We show that the $n$ distributions in such wave packets can be controlled during production by the size and shape of the generating field and further tailored through the application, after production, of precisely timed half-cycle pulses. The remarkable level of precision that can be achieved is demonstrated using time domain spectroscopy. The protocols employed are described with the aid of ``quantized'' classical trajectory Monte Carlo simulations. Research supported by the NSF, the Robert A. Welch Foundation, the OBES, U.S. DoE to ORNL, and by the FWF (Austria).