Graphene-mediated near field thermostat based on three-body photon tunneling

We theoretically demonstrate a near field thermostat based on the mechanism of three-body photon heat tunneling and tunability of graphene. The system consists of three separated parallel plates at different temperatures, with the hot and cold body (located at either side of the system) coated with a monolayer of graphene. As a unique two-dimensional material, graphene owns the tunable plasmonic dispersion relation which can be rapidly modulated by changing its chemical potential in an electronical manner. By changing the chemical potentials of graphene, the near field radiative heat flux (NFRHF) transporting in the system can be tuned accordingly. As a consequence, the equilibrium temperature of the intermediate body can be adjusted from the temperature of the hot body to that of the cold one. The results show that the equilibrium temperature can be adjusted from 326 K to 388 K in SiO2-SiO2-SiO2 configuration, which occupies about sixty percent of the temperature range with respect to the cold and hot body. This phenomenon implies that near field contactless temperature adjustment can be carried out by the proposed configuration. The underlying mechanism is attributed to the varied NFRHF with tunable surface plasmon polaritons of graphene. Moreover, three-body photon heat tunneling can benefit the regulation function of the system in the near field regime and an enhanced region for adjusting temperature is observed. An interesting phenomenon is observed that the mismatch between different materials raises the regulation ability to 82 K in SiO2-SiC-SiO2 configuration. The results obtained in this study could find significant applications in the field of near field thermal management and controlling temperature in the separation of micrometer and millimeter scale, especially paves a new way toward improving the performance of near field thermal transistor based on insulator-metal transition material.