  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.
