On Super-Planckian thermal emission in far field regime

TL;DR

This paper demonstrates that finite size systems can exhibit super-Planckian thermal emission in the far-field regime, surpassing blackbody limits, unlike indefinite planar media which are bounded by blackbody emission.

Contribution

It provides a theoretical proof that finite systems can achieve super-Planckian thermal emission, challenging the traditional blackbody limit for far-field thermal radiation.

Findings

Finite systems can emit more than blackbody limits in the far-field.

Indefinite planar media are bounded by blackbody emission.

Super-Planckian emission is theoretically possible in finite size systems.

Abstract

We study, in the framework of the Landauer theory, the thermal emission in far-field regime, of arbitrary indefinite planar media and finite size systems. We prove that the flux radiated by the former is bounded by the blackbody emission while, for the second, there is in principle, no upper limit demonstrating so the possibility for a super-Planckian thermal emission with finite size systems.