Abstract
Near-field radiative heat transfer (RHT) can surpass Planck's blackbody limit by several orders of magnitude due to the tunneling effect of thermal photons. The ability to understand and regulate RHT is of great significance in contactless energy transfer. In this work, we construct a rotating system with a hexagonal boron nitride (h-BN) cylinder for actively regulating the RHT between two nanoparticles (NPs). The results show that when the two NPs are located directly above the cylinder, energy can be directionally transmitted along the cylindrical channel in the form of low-loss surface waves, which can significantly enhance RHT. In addition, we find that the RHT can be regulated by actively manipulating the excitation of cylindrical surface modes. When the rotation point is located in the middle of the line connecting the two NPs, the modulation contrast approaches five orders of magnitude, higher than that of cylinders made of other materials under the same conditions. When its diameter is slightly less than the distance between NPs, the h-BN cylinder shows excellent tunability in the heat exchange. The present work may offer a theoretical possibility for actively regulating and controlling near-field RHT between arbitrary objects based on cylindrical waveguides.