Phase dependence in the ionization of atoms by intense one-cycle laser pulses within the Landau-Dykhne approximation

The phase sensitivity of the atomic ionization by intense one-cycle linearly polarized laser pulses is discussed within the analytic Landau-Dykhne approximation. The generalized Keldysh parameter is introduced for analysis of two regimes of ionization. In the case of super-intense laser field we found that ionization by cosine waveform pulse is much more effective than that by sine waveform pulse with the same energy in the pulse. This is a pure quantum destructive interference effect. Electron energy spectra and effective electron temperatures are also derived analytically for both waveform pulses