  It is shown that a graphene layer on top of a dielectric slab can
dramatically influence the ability of this dielectric for radiative heat
exchange. Effect of graphene is related to thermally excited plasmons.
Frequency of these resonances lies in the terahertz region and can be tuned by
varying the Fermi level through doping or gating. Heat transfer between two
dielectrics covered with graphene can be larger than that between best known
materials and even much larger at low temperatures. Moreover, high heat
transfer can be significantly modulated by electrical means that opens up new
possibilities for very fast manipulations with the heat flux.
