With the classical three-dimensional ensemble model, we have investigated the microscopic recollision dynamics in nonsequential double ionization of helium by 800-nm laser pulses at $2.0\hspace{0.5em}\mathrm{PW}/{\mathrm{cm}}^2$. We demonstrate that the asymmetric energy sharing between the two electrons at recollision plays a decisive role in forming the experimentally observed $\mathsf{V}$-shaped structure in the correlated longitudinal electron momentum spectrum at the high laser intensity [Phys. Rev. Lett. 99, 263003 (2007)]. This asymmetric energy-sharing recollision leaves footprints on the transverse electron momentum spectra, which provide insight into the attosecond three-body interactions.

• Received 29 July 2010

DOI:https://doi.org/10.1103/PhysRevA.82.053402