Manipulating the shape of electronic non-dispersive wave-packets in the   hydrogen atom: numerical tests in realistic experimental conditions
  We show that combination of a linearly polarized resonant microwave field and a parallel static electric field may be used to create a non-dispersive electronic wavepacket in Rydberg atoms. The static electric field allows for manipulation of the shape of the elliptical trajectory the wavepacket is propagating on. Exact quantum numerical calculations for realistic experimental parameters show that the wavepacket evolving on a linear orbit can be very easily prepared in a laboratory either by a direct optical excitation or by preparing an atom in an extremal Stark state and then slowly switching on the microwave field. The latter scheme seems to be very resistant to experimental imperfections. Once the wavepacket on the linear orbit is excited, the static field may be used to manipulate the shape of the orbit. 
Dominique Delande, Krzysztof Sacha, and Jakub Zakrzewski