▎ 摘 要
We discuss the nonradiative heat transfer in a nonequilibrium double-layer graphene system. We show that at the neutrality point the heat exchange is dominated by the interlayer 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 a much more efficient heat exchanger than conventional metals. The physical reason behind this phenomenon is the presence of interband excitations with a large energy, and a small momentum in the graphene spectrum. The 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.