The dynamics of high Rydberg states in the presence of time-dependent inhomogeneous fields

This paper presents calculations of the evolution of an optically prepared Rydberg wavepacket in the presence of time-dependent inhomogeneous electric fields and the results have relevance to the stabilization of Rydberg stat es as appropriate to ZEKE spectroscopy. The field is considered to arise fr om the combination of an applied field, which may be ramped in time, and th e presence of microscopic charges, e.g., a pseudo-random distribution of io ns, whose positions may also change with time. The results of the calculati ons lead to a clearer definition of the conditions under which Rydberg stab ilization is achieved, such as in field switching experiments (Baranov et a l., Chem. Phys. Lett., 1998, 291, 311), and also confirm the mechanisms by which the randomization of population between blue-shifted and red-shifted Stark states occurs in the presence of micro-fields due to ions (Palm et al ., Philos. Trans. R. Soc. London, Ser. A, 1997, 355, 1551). The motion of t he ions is found to have a significant m-locking effect in the calculations , providing a possible mechanism for the commonly observed long-lifetime ta il in the population decay of high-n Rydberg states.