Bound states of atomic hydrogen in a laser field beyond the nonrelativistic dipole approximation.

Abstract

Recent calculations on the bound states of atomic hydrogen in a laser field in the nonrelativistic dipole approximation have produced metastable states with decreasing binding energy as a function of ${\mathrm{\ensuremath{\alpha}}}_{0}$\ensuremath{\sim}${\mathit{I}}^{1/2}$${\mathrm{\ensuremath{\omega}}}^{\mathrm{\ensuremath{-}}2}$ (where I is the laser intensity and \ensuremath{\omega} is its frequency). We extend the calculations by removing these restrictions. We find the limit of validity of the previous calculations and find that beyond this limit of ${\mathrm{\ensuremath{\alpha}}}_{0}$ the lowest bound state persists but that its character is completely changed.