Enhanced radiative heat transfer via propagating surface modes in a dielectric nanowire

The photon-mediated radiative heat transfer (RHT) in the near-field regime decays dramatically with the increase of the separation distance. It is an open problem in applied physics to realize super-Planckian transport behaviors over long distances. This work aims to theoretically explore RHT in a many-body system consisting of nanoparticles (NPs) and a dielectric nanowire (NW). The results show that the coupling effect of localized surface phonon polaritons (SPhPs) with propagating surface modes can enhance the RHT between two interacting NPs. The maximum enhancement ratio in the presence of a NW can reach up to five orders of magnitude, higher than that of the thin film and semi-infinite slab under the same conditions. In addition, we construct a dual waveguide system consisting of a one-dimensional linear NP array and a NW. Due to the synergistic effect between the strong interactions of localized SPhPs and the propagating surface modes along the NW, the dual waveguide mode can compensate for the decrease in RHT due to the increase in spacing, thus achieving ultrastrong, long-range energy transport between NPs at both ends. The present work has potential applications in the contactless energy conversion and management of optoelectronic devices at the micro- and nanoscale.