Correlation effects in two-electron model atoms in intense laser fields

We report an efficient implementation of a spatial two-zone method for solving Schrödinger’s equation numerically, using a canonical basis set decomposition, and also its application to two-electron wave functions in a study of double multiphoton ionization. We make the first calculation of the time-dependent degree of electron correlation for this poorly understood process. Our results show a particularly sensitive window of intensities coinciding exactly with the well-known “knee” regime in ion-count data.