Andrey K. KAZANSKY (Univ. St. Petersburg, Russia and IMS), Valentine N. OSTROVSKY (Univ. St. Petersburg, Russia and IMS) and Hiroki Nakamura
[Laser Phys. 7, 1 (1997)]
Time evolution of a hydrogen Rydberg atom placed in homogeneous electric and magnetic fields with an arbitrary time dependence is considered. Within the manifold of electronic states with the same principal quantum number n, the problem is effectively reduced to solution of two independent two-state problems. Thus, the "dressed states" are constructed which account exactly for all intrashell transitions. For the time-periodic fields, the general structure of the quasienergy spectrum is recovered as two equidistant overlaying patterns. The Rydberg atom placed in the monochromatic elliptically polarized electric fields with a possible presence of its static component and of the static magnetic field is considered in more detail as a generic case. We show that by varying the fields parameters the whole quasienergy spectrum could be shrinked to zero. The possible applications of this effect are discussed. The revivals of Rydberg wave packets and the possibility of complete population transfer (or quantum control) are also analyzed.