Dissociative multiple ionization of argon trimers and tetramers in two-color femtosecond laser fields.

This article focuses on the experimental investigation of dissociative multiple ionization of argon trimers and tetramers induced by relative phase-controlled linearly and elliptically polarized two-color femtosecond laser fields. Using cold target recoil ion momentum spectroscopy (COLTRIMS), the study measures momentum distributions and kinetic energy releases of ionic fragments to reveal orientation-dependent fragmentation patterns. The results demonstrate that tuning the relative phase of the two-color laser fields enables directional control over triple and quadruple ionization processes, primarily explained by the mechanism of enhanced ionization, while electron recollision plays a negligible role. These findings advance the understanding of van der Waals bond breaking in weakly bound rare gas clusters and suggest new avenues for controlling molecular fragmentation with ultrafast laser pulses.