Core-polarization-corrected random-phase approximation with exact exchange for dipole surface plasmons in silver clusters

Abstract

The surface plasmon in silver clusters is red shifted with respect to standard jellium random-phase approximation (RPA) predictions that work well for simple metal clusters. The reason for the deviation arises primarily from the non-negligible polarization interaction between the valence electrons and ionic cores. In order to quantify this effect in the jellium approximation we introduce a modified RPAE (RPA with exact exchange). The jellium background of Ag cores is treated as a polarizable sphere. This model predicts a dipole surface resonance in excellent agreement with published experimental data. Moreover it yields the blue shift (red shift) with decreasing sizes for cationic (anionic) Ag clusters as observed experimentally.