An analytical quantum model for intense field processes: quantum origin of rescattering plateaus

Abstract

After a brief comparison of two basic quantum approaches for the analytic treatment of strong laser field phenomena, we analyse the spatial and temporal dependences of the quasistationary, quasienergy state wavefunction Φ(r, t) of a weakly bound level in a strong laser field. We find from this analysis that the characteristic high-energy plateau structures in the spectra of laser–atom processes originate from similar plateau features in the spectra of the Fourier-harmonic components, Φn(r), of Φ(r, t). Together with a quantum interpretation of the well-known rescattering scenario in terms of these wavefunctions, the results of this analysis provide an explanation for the drastic difference between HHG and ATI/ATD in the sensitivity of plateau structures to binding potential effects.