Excitation and Fission in Alkali-Atom Clusters

Abstract

The study of the electronic structure of clusters is subjected to various experimental and theoretical approches. Currently used are the evolution with size of ionization potentials, static polarizabilities, collective excitation and stability against an excess of charge or internal energy. Results are interpreted in terms of simple models as the classical metallic drop, successefully applied to alkali-atom clusters, or with quantum mechanical models which reproduce in more details the variations with size. Here we present new results obtained for alkali-atom clusters in two different domains. First we have analyzed in details the fission of doubly charged potassium clusters around the critical size of stability. Second we have studied the response of singly ionized potassium clusters K ⁺_n to an external electromagnetic field, in an extended domain of size.