Coulomb effects in photon-momentum partitioning during atomic ionization by intense linearly polarized light

Partitioning of photon momenta between the ion and electron in photoionization and the involved subcycle dynamics are investigated using an extended semiclassical model, where momentum transfer from the photon to the electron-ion system via the (magnetic) Lorentz force is taken into account. It is found that in both the tunneling and rescattering processes, Coulomb attraction between the ion and electron plays a role in the momentum partitioning. The effect is especially important for linearly polarized light since the photons that lift the electron out of the bound state do not always contribute to the forward ion momentum. The present results can have important implications in the generation of terahertz radiation and the calibration of tunnel exit by measuring final ion longitudinal momentum. DOI: 10.1103/PhysRevA.87.041403