Thermal Switching of Near-Field Radiative Heat Transfer Between Nanoparticles via Multilayered Surface Modes

Abstract

We theoretically demonstrate near-field radiative thermal switching between two nanoparticles located above a multilayered slab. We propose a multilayered structure composed of $\mathrm{Si}\mathrm{C}$ and the phase transition material ${\mathrm{VO}}_{2}$. The high tunability of the multilayered structure enables the active modulation of surface polaritons when combined with the phase transition feature of ${\mathrm{VO}}_{2}$, overcoming the intrinsic resonance of the thermal radiation of ${\mathrm{VO}}_{2}$. Utilizing this feature, the surface polaritons enormously excited at the particle's resonant frequency above the multilayer can be switched on or off, resulting in the efficient modulation of heat flux between nanoparticles. The effects of interparticle distance and multilayer parameters on thermal switching ratios are investigated. We demonstrate that the multilayer with metallic ${\mathrm{VO}}_{2}$ can significantly inhibit the heat flux between particles as a result of the destructive interference between direct and reflected waves. The excited surface modes above the multilayer with insulating ${\mathrm{VO}}_{2}$ can still improve the heat flux between nanoparticles, resulting in a thermal switching ratio of ${10}^{\ensuremath{-}5}$ at the particle resonant frequency at a large interparticle distance.