MICROSCOPIC STRUCTURE OF THE PLASMA RESONANCE IN CHARGED POTASSIUM MICROCLUSTERS

The dipole strength function of K9+, K21+, and K222+ charged microclusters is calculated within the framework of the random-phase approximation. Contrary to the case of neutral clusters, essentially no Landau damping is found in the systems under study here, the spectrum being dominated by a single peak carrying most of the oscillator strength. The coupling of the plasmon to thermal fluctuations of the surface can account for about 60% of the observed spreading width. © 1990 The American Physical Society.