The desorption dynamics of rubidium dimers (Rb_2) off the surface of helium nanodroplets induced by laser excitation is studied employing both nanosecond and femtosecond ion imaging spectroscopy. Similarly to alkali metal atoms, we find that the Rb_2 desorption process resembles the dissociation of a diatomic molecule. However, both angular and energy distributions of detected Rb_2^+ ions appear to be most crucially determined by the Rb_2 intramolecular degrees of freedom rather than by those of the Rb_2He_N complex. The pump-probe dynamics of Rb_2^+ is found to be slower than that of Rb^+ pointing at a weaker effective guest-host repulsion for excited molecules than for single atoms.
@article{arxiv.1608.06463,
title = {Desorption Dynamics of Rb_2 Molecules off the Surface of Helium Nanodroplets},
author = {A. Sieg and J. von Vangerow and F. Stienkemeier and O. Dulieu and M. Mudrich},
journal= {arXiv preprint arXiv:1608.06463},
year = {2017}
}