Analytical ATI spectrum of an exactly solvable 3D model of laser-atom interaction

Abstract
Starting from the stationary quantum Hamiltonian and using the theory of resolvence the authors rigorously define and analytically derive the stationary intrinsic ATI spectrum of an exactly solvable 3D model of laser-atom interaction. The result permits them to determine the phenomena of switching, suppression and disappearance of the ATI peaks as a function of the field intensity. The dependence of the ATI spectrum on the field modified ionisation gap and the broadening of the initial bound state are investigated. The modification of these spectra due to ponderomotive acceleration is also shown. The results are discussed with graphical illustrations and their implications for ATI in general are pointed out.