The Kicked Rydberg Atom: Exploring the Ultra-fast Ultra-intense Regime at Nanosecond Timescales

With the development of high-intensity femto-second laser systems there is increasing interest in the response of atoms to pulsed electric fields with timescales comparable to the classical electron orbital period, T$_{n}$, and field strengths sufficient to dominate the electron motion. We show that the essential physics of such interactions can be explored under less extreme conditions using very-high-$n$ Rydberg atoms ($n\ge $350) subject to unidirectional pulsed electric fields, termed half-cycle pulses (HCPs), with durations T$_{p}<<$T$_{n}$. Particular interest centers on modeling the effect of a freely-propagating train of attosecond HCPs which it is suggested might be used to engineer atomic wavefunctions. Such a pulse train, for which the net field experienced by an atom is zero, is modeled using a train of HCPs upon which is superposed a variable offset dc field. The presence of an offset field leads to dramatic changes in the dynamics and overall survival probability, the latter peaking when the average field experienced by an atom is zero. This behavior is discussed with the aid of CTMC simulations and results from population trapping near the continuum.