SEMICLASSICAL DYNAMICS OF CIRCULAR-ORBIT RYDBERG WAVE-PACKETS

A semiclassical propagator is applied to describe the dynamics of circ ular-orbit wave packets which are initially well localized in three di mensions. A sum over classical Kepler trajectories for the wave-packet autocorrelation function is obtained which is extremely accurate well past the classical regime of the evolution of the wave packet. The no nclassical nature of the wave-packet evolution at long times is associ ated with the interference between amplitudes from classical paths at different energies. The time scale of the wave-packet revivals is rela ted to the shearing rate of the corresponding classical ensemble.