Effects of dielectric function on near-field radiation between two spherical nanoparticles

When the distance between two nanoparticles becomes less than the mean free path or the characteristic wavelength of radiation, the radiative heat transfer will be several orders of magnitude greater than that between two blackbodies. The remarkable increased radiation energy transfer may be harmful to the performance of super-insulating materials such as silica aerogels with nanoporous structures. Based on the fluctuation-dissipation theorem, the near-field radiation can be suppressed effectively by tuning the adjustable parameters in dielectric function of Drude and Lorentz models. This study is of great significance for investigating the heat transfer of group nanoparticles and developing novel insulating materials with special properties.