Stabilization window and attosecond pulse train production at atom ionization in superintense laser field

We present the results of numerical experiments on a two-dimensional model atom driven by a high-intense laser pulse. The electron wave-packet behavio r is studied in a range of laser parameters corresponding to the dynamic st abilization regime. Wave packet localization in this regime with arbitrary laser polarizations is shown to manifest itself macroscopically by high-ord er harmonic production in the form of long trains of attosecond pulses. Cal culations for the sub-relativistic regime of laser-atom interaction are car ried out without making the dipole approximation in order to take into acco unt the Lorentz force effect in wave packet evolution. The transition from polychotomy to the magnetic-field-induced drifting at very high laser inten sities is documented which results in the electron delocalization. As a con sequence, the intensity dependence of the atomic survival probability as we ll as that of the efficiency of high-order harmonic production possess a wi de "stabilization window" followed by an abrupt drop because of the magneti c field effect. (C) 2000 Optical Society of America.