MECHANISM OF LASER-INDUCED DOUBLE-IONIZATION OF HELIUM

In a series of recent experiments anomalously large probabilities of l aser-induced double ionization of the He atom have been observed. In t his letter we analyse the clearest observation of this phenomenon, ove r a signal range of many orders of magnitude, by Walker et al. The ana lysis is carried out using a newly developed intense-field many-body S -matrix theory. For the first time good agreement between the experime ntal data and a theory is found. It is shown that the dominant mechani sm behind the observed large probability of laser-induced double escap e is a quantum mechanical process of absorption of photon energy by on e of the electrons which is shared cooperatively with the other electr on through the Coulomb correlation; quantitatively it turns out to be one of the largest effects of electron-electron correlation known in a tomic physics.