Plasmonic Tuning of the Near Field Heat Transfer in Double Layer Graphene

Abstract: We discuss the non-radiative heat transfer in non-equilibrium double layer graphene system. We show that at the neutrality point the heat exchange is dominated by the inter-layer plasmon modes and derive analytic expressions for the heat current as a function of temperature and the interlayer separation. These results show that for a range of low temperatures the two graphene layers are much more efficient heat exchanger than conventional metals. The physical reason behind this phenomenon is the presence of inter-band excitations with a large energy, and a small momentum in graphene spectrum. Plasmonic mechanism of the heat transfer is sharply suppressed by electrostatic doping. This allows for tuning of the heat exchange by a small applied voltage between the two layers.