Fluctuation-driven thermal transport in graphene double-layers at charge neutrality

We develop a theory of fluctuation-driven phenomena in thermal transport graphene double-layers. work the regime electron hydrodynamics and focus on double-charge neutrality point. Although at point charge is decoupled from hydrodynamic flow, fluctuations density cause both drag heat transfer between layers. The bilayer system governed by these two phenomena. express friction coefficient interlayer conductivity terms distance intrinsic liquid. then obtain conductance matrix determine spatial dependence velocity temperature system. For shorter resistance determined drag. In longer systems situation perfect realized, which velocities layers become equal interior systems. Estimates are given for monolayer devices. predictions our can be tested high-resolution imaging Johnson-Nyquist nonlocal noise thermometry.