Optical near-field resonances in the system of interacting nanoparticles

Near-field interaction of two metallic nanoparticles is considered at small spacings between their centers in the field of an external optical radiation. Effective polarizations of valence electrons in nanoparticles are calculated with allowance for their interactions with the ion core. The effective polarizations are shown to contain near-field resonances whose frequencies differ substantially from the frequencies of resonances in isolated nanoparticles, and to depend on the distance between the centers of the nanoparticles and on the polarization of the external field with respect to the axis that connects the nanoparticle centers.