ON ELECTRONIC SHELLS SURROUNDING CHARGED INSULATED METALLIC CLUSTERS

We determine the wavefunctions of electrons bound to a positively charged mesoscopic metallic cluster covered by an insulating surface layer. The radius of the metal core and the thickness of the insulating surface layer are of the order of a couple of Angstrom. We study, in particular, the electromagnetic decay of externally located electrons into unoccupied internally located states that exhibit a resonance behavior. This resonance structure has the consequence that the lifetime of the "mesoscopic atoms" may vary by up to six orders of magnitude depending on the values of the parameters (from seconds to years).