Abstract. Surface plasmon polariton resonance in metallic clusters embedded in a matrix is broadened due to the interface decay channel of the plasmon lifetime. This non-classical broadening effect is caused by adsorbate-induced local density of states near the Fermi level of the cluster. We study theoretically the broadening effect for realistic small noble clusters extending Persson's theory for adsorbate-induced damping of the plasmon resonance by taking into account the interband transitions in the dielectric function of the cluster. The broadening of the surface plasmon resonance caused by the interface decay channel is significantly influenced by the interband transitions in the metallic cluster.

Received 30 July 2003
Published 13 November 2003