Plasmonic nature of van der Waals forces between nanoparticles

We propose a new approach to calculate van der Waals forces between nanoparticles where the van der Waals energy can be reduced to the energy of elementary surface plasmon oscillations in nanoparticles. The general theory is applied to describe the interaction between 2 metallic nanoparticles and between a nanoparticle and a perfectly conducting plane. Our results could be used to prove experimentally the existence of plasmonic molecules and to elaborate new control mechanisms for the adherence of nanoparticles between each other or onto surfaces.