  In this letter, we have demonstrated the possibility to efficiently relay the
radiative heat flux between two nanoparticles by opening a smooth channel for
heat transfer. By coating the nanoparticles with a silica shell and modifying
the substrate with multilayered graphene sheets respectively, the localized
phonon polaritons excited near the nanoparticles can couple with the multiple
surface plasmon polaritons near the substrate to realize the heat relay in the
long distance. The heat transfer can be enhanced by more than six orders of
magnitude and the relay distance can be as high as 35 times in the far-field
regime. The work may provide a way to realize the energy modulation or thermal
communications especially in long distance.
