Phase control of the Rydberg atom ionization degree by a strong laser field

It is shown that due to the arrangement of a specific superposition of the Rydberg states one may control the rate and the degree of atom ionization. This effect results from the Raman interaction of the Rydberg levels through resonant underlying atom levels. Depending on the initial population of an atom in interaction with a strong laser field it is either completely ionized or demonstrates very high degree of stability. It is shown that the states that are either resistant to the ionization decay or, vice versa, decaying into continuum may be arranged by means of double laser pulses with delay controlled time