Mechanism of delayed double ionization in a strong laser field
  When intense laser pulses release correlated electrons, the time delay between the ionizations may last more than one laser cycle. We show that this "Recollision-Excitation with Subsequent Ionization" pathway originates from the inner electron being promoted to a sticky region by a recollision where it is trapped for a long time before ionizing. We identify the mechanism which regulates this region, and predict oscillations in the double ionization yield with laser intensity. 
Francois Mauger (CPT), Adam Kamor, Cristel Chandre (CPT), Turgay Uzer
physics.atom-ph