Near-field radiative heat transfer in three-body system based on topological insulator Bi2Se3

This study investigates the near-field radiative heat flux in a three-body system made of Bi2Se3, a topological insulator that supports hyperbolic phonon polaritons (HPPs) in the terahertz frequency range. We demonstrate that the near-field radiative heat flux in the three-body system made of Bi2Se3 is remarkably enhanced compared to the two-body counterpart. The thickness of the intermediate body or the chemical potential of Bi2Se3 can be used to control the radiative heat flux. Our numerical results reveal that the heat flux initially increases and then decreases with the thickness of the intermediate body, indicating that an optimal heat flux can be obtained by selecting an appropriate chemical potential and intermediate body thickness. Moreover, increasing the chemical potential of Bi2Se3 shifts the hybrid surface plasmon phonon polaritons, which arise from the coupling of surface plasmons and HPPs, toward higher frequencies. These findings have important implications for developing thermal devices such as thermal transistors and offer a promising approach to modulating near-field radiative heat transfer and thermal management.