Ionization and excitation dynamics of H(1s) in short intense laser pulses -: art. no. 033418

We present an analysis of the ionization and excitation dynamics of H(1 s) when exposed to an ultrashort and intense laser pulse. The studies are based on quantum close-coupling calculations and classical trajectory Monte Carlo simulations. The quantum and classical approaches are compared at three different levels: (i) Total (ii) differential ionization probabilities, and (iii) a direct comparison of the dynamics during the laser pulse from snapshots of the spatial electronic probability density. For short and intense pulses, the results of the two methods are in fair agreement. We show that the direction of ejection of the ionized electron is very asymmetric and strongly sensitive to the initial phase of the electric field.