Radiative heat transfer at the nanoscale

Abstract

Macroscopic objects at thermal equilibrium emit electromagnetic radiation which is in equilibrium with the objects. If two bodies have different temperatures, they can exchange heat without contact by means of the emitted thermal radiation. For separations large enough between the bodies, the power exchanged is described by the well-known Stefan-Boltzmann law and is bounded by the backbody limit. But, what happens when the gap between the two of them is reduced to much smaller distances? At the nanoscale, the blackbody limit law can be exceeded by several orders of magnitude due to the contribution of evanescent waves standing close to the surfaces of the bodies. In this TFG, we study this phenomenon at a theoretical level and numerically calculate the heat flux between to semi-infinite bodies considering concrete materials such as silicon carbide and gold