Does a delta function atom interacting with a superstrong laser pulse exhibitstabilization?

Abstract

Calculations by the state-specific expansion approach of the time-dependent ionization probability of a one-dimensional delta function atom ionized by smooth laser pulses with peak intensity up to 8.75 × 1017 W cm-2 and frequency of 1 or 1.5 au, show that the suppression of the ionization probability, predicted for this system by Su et al (1996 J. Phys. B: At. Mol. Opt. Phys. 29 5755), is absent. The above-threshold ionization spectrum for five values of peak intensity, between 2.45 × 1016 and 7.7 × 1017 W cm-2, was also computed. We suggest that only when the contribution of the free-free transitions of any model or real system is accounted for rigorously, can definitive conclusions about the superstrong field regime be drawn.