Quantum effects on optical properties of a pair of plasmonic particles separated by a subnanometer gap

The discrete source method is used to study the influence exerted by nonlocal screening on the optical properties of a linear cluster of nonspherical plasmonic nanoparticles separated by a subnanometer gap. It is shown that deformations of the particles and a reduction in the interparticle gap size lead to an enhanced nonlocal screening effect. It is found that an increase in both scattered and near field intensities is blocked by the nonlocal effect, and deformations of the particles can be used as an alternative to field intensity enhancement.