Аннотация:A comparative analysis of the behavior of optical characteristics of paired silver and sodium nanoparticles with a nanometer gap between them was performed using the discrete source method. The emerging quantum effects were considered based on mesoscopic boundary conditions using the Feibelman parameters. It was found that the presence of the quantum effect in silver leads to a decrease in the plasmon resonance amplitude and its shift to the short-wavelength region, whereas for sodium particles an increase in the plasmon resonance amplitude and a shift to the long-wavelength region, which can exceed 35 nm, are observed. A study of the field intensity distribution on the particle surface at the plasmon resonance frequency showed that the maxima are achieved at the ends of the particles, and the absolute maximum is located near the gap. At the same time, at distances of about 10 nm along the particle surface, the intensity change can reach 4 orders of magnitude, which is quite significant if we consider that such a distance is only 1.5% of the radiation wavelength in the environment.
