Electron-electron correlation in laser-induced nonsequential double ionization

The distributions of the momenta of the two electrons liberated in nonsequential double ionization of neon and argon are calculated in the S-matrix formalism assuming a rescattering scenario. Two different forms for the electron-electron correlation are compared: the Coulomb repulsion in the Born approximation and a three-body contact interaction including the ion. The former favors disparate momenta of the two electrons, the latter equal momenta.