Modulation and splitting of three-body radiative heat flux via graphene/SiC core-shell nanoparticles

•We investigate radiative heat transfer among three graphene/SiC core-shell nanoparticles.•The excitation of multiple photon tunneling modes are analyzed.•A near-field thermal modulator with a thermal modulation ratio >40 is realized.•Tuning Fermi level of graphene shells enables the heat splitting ratio to exceed 99. We theoretically demonstrate the modulation and splitting of radiative heat flux in a three-body system consisting of graphene/SiC core-shell (GSCS) nanoparticles on the basis of their highly tunable polarizabilities, which play a dominant role in the coupling of localized surface resonance. The excitation of multiple photon tunneling modes enables the radiative heat transfer to be controlled in different scenarios. Using the dependence of photon tunneling on the Fermi level and radius of the intermediate GSCS nanoparticle, such a many-body system not only holds the potential to be a near-field thermal modulator with a thermal modulation ratio greater than 40, but also allows the heat splitting effect with the ratio over 99 when the intermediate particle becomes the hot source. This work may facilitate dynamical thermal management in a many-body system, and can also benefit the plasmonics community in the near future.