Nonsequential Double Recombination in Intense Laser Fields
Abstract
A second plateau in the harmonic spectra of laser-driven two-electron atoms is observed both in the numerical solution of a low-dimensional model helium atom and using an extended strong field approximation. It is shown that the harmonics well beyond the usual cut-off are due to the simultaneous recombination of the two electrons, which were emitted during different, previous half-cycles. The new cut-off is explained in terms of classical trajectories. Classical predictions and the time-frequency analysis of the ab initio quantum results are in excellent agreement. The mechanism corresponds to the inverse single photon double ionization process in the presence of a (low frequency) laser field.
Cite
@article{arxiv.physics/0609010,
title = {Nonsequential Double Recombination in Intense Laser Fields},
author = {P. Koval and F. Wilken and D. Bauer and C. H. Keitel},
journal= {arXiv preprint arXiv:physics/0609010},
year = {2009}
}
Comments
4 pages, RevTeX, v2 with an extended strong field approximation treatment of the process; instead, v1 describes an attosecond control scheme to enhance the process