Testing electron correlation in Helium using attosecond pulses

Using a full quantum model beyond the one dimensional model, we are able to study the double correlated double ionization of Helium in several regimes. For example in the near IR, we have investigated the correlated momentum distribution of both electrons from nonsequential double ionization of helium in a λ=800 nm laser, with intensity I=4.5 x 1014 W/cm2. We observe a finger-like structure in the correlated electron momentum distribution that can be interpreted as a signature of the microscopic dynamics in the recollision process. To study related process such as the excitation by recollision we make use of attosecond pulses to probe the dynamics of ionization. In this paper we introduce this novel technique to study the interaction that could lead increase the accuracy of the description of the correlated processes.