  Using the fluctuational electrodynamics and nonequilibrium Green's function
methods, we demonstrate the existence of a current-induced heat transfer in
double-layer graphene even when the temperatures of the two sheets are the
same. The heat flux is quadratically dependent on the current. When
temperatures are different, external voltage bias can reverse the direction of
heat flow. The drift effect can exist in both macroscopic and nanosized
double-layer graphene and extend to any other 2D electron systems. These
results pave the way for a different approach to the thermal management through
radiation in nonequilibrium systems.
