Laboratoire Collisions Agrégats Réactivité - UMR5589

The ultrafast geometrical rearrangement dynamics of NO doped cryogenic Ne matrices after femtosecond laser pulse excitation is studied using a quantum dynamical approach based on a multi-dimensional shell model, with the shell radii being the dynamical variables. The Ne-NO interaction been only weakly anisotropic allows the model to account for the main dynamical features of the rare gas solid. Employing quantum wave-packet propagation within the time dependent Hartree approximation, both, the static deformation of the solid due to the impurity and the dynamical response after femtosecond excitation, are analysed. The photoinduced dynamics of the surrounding rare gas atoms is found to be a complex high-dimensional process. The approach allow to consider realistic time-dependent femtosecond pulses and the effect of pulse duration is clearly shown. Finally, using the real pulse parameters of previous experiments, pump-pulse signals are calculated and found to be in good agreement with experimental results, allowing for a clear analysis of the ultrafast mechanism of the energy transfer into the solid.