Realization of the kicked atom

The kicked atom is realized experimentally by exposing potassium $\mathrm{np}$ Rydberg atoms with $n\sim 388$ to a sequence of up to 50 half-cycle pulses whose duration is much shorter than the classical electron orbital period. The Rydberg atom survival probability is observed to have a broad maximum for pulse repetition frequencies near the classical orbital frequency. Comparisons with detailed classical trajectory Monte Carlo simulations show that this behavior provides an unambiguous signature of dynamical stabilization. The classical simulations further show that the kicked hydrogen atom is, depending on the pulse repetition frequency, chaotic or characterized by a mixed phase space with various families of fully stable islands within which the atom is stable against ionization. Signatures of stabilization and chaotic diffusion are also observed in the final bound-state distribution of the surviving atoms.