Focus

The recollision process in atomic or molecular systems subjected to strong and short linearly polarized laser pulses is the keystone process in attosecond science. This recollision follows from the three step model where a pre-ionized electron (the outer electron) is driven back to the core, by the laser, to collide with another electron still bound to the core. This recollision is a nonlinear and complex phenomenon which may result, for instance, in the emission of two correlated electrons. Here we focus on the dynamics of recollision. We show that, because of its fast motion, the outer electron can be somehow removed from the system: The bound electron is subjected to a kick by the outer electron which may result in its ionization if the kick intensity is large enough. As a test for our model, we derive a discrete time area-preserving map (see picture) which captures the bare essentials of the recollision process and enables theoretical predictions on the double ionization yields, a commonly experimentally measured data.

Associated publications