Excitation of a three-dimensionally localized atomic electron wave packet

We have prepared an atomic electron in a three-dimensionally localized wave packet that travels along a highly eccentric orbit between the nucleus and a:turning point approximately 1000 Angstrom away. State preparation consisted of two distinct steps. First: the;electron wave function was localized to the desired orbit by exciting a stationary extreme Stark state from the n = 30 manifold of a sodium atom in a de electric field. Then the dynamic wave packet was formed by applying a terahertz electromagnetic half-cycle pulse polarized along the direction of the dc-field. The localized state is an ideal starting point for further quantum control proceeding along classical orbits.