Embedded metal cluster in strong laser fields

We discuss microscopic mechanisms of the violent dynamics following strong laser excitation of a metal cluster embedded in a rare gas matrix, taking as test case Na-8@Ar-434. This covers at least two aspects: first, it represents the typical experimental situation of metal clusters handled in rare gas matrices or a finite drop of surrounding rare gas material, and second, it serves as a generic test case for highly excited chromophores in inert surroundings addressing questions of energy transport and perturbation of the medium. We simulate the process up to 10 ps using a mixed quantum-mechanical (for the electrons) and classical (ions and atoms) approach and analyze the emerging dynamics with respect to all basic constituents: cluster electrons, cluster ions, and matrix atoms. We find several stages of relaxation taking place with time scales from a few fs to over a few ps and much slower processes remaining for long after the simulation. A particularly interesting aspect is that the surrounding rare gas material stabilizes a highly charged metal cluster which would otherwise explode without delay. (C) 2007 Elsevier B.V. All rights reserved.