Correlated Multielectron Dynamics in Ultrafast Laser Pulse Interactions with Atoms

We present the results of the detailed experimental study of multiple ionization of Ne and Ar by 25 and 7fs laser pulses. Whereas in multiple ionization of Ar different mechanisms, involving field ionization steps and recollision-induced excitations, play a role, for Ne only one channel, where the highly correlated instantaneous emission of up to four electrons is triggered by a recollisional electron impact, is found to be important. Using few-cycle pulses we are able to suppress those processes that occur on time scales longer than one laser cycle.