Far-field heat transfer maximization through controlled polariton coupling between deep-subwavelength polar membranes

Abstract

We demonstrate the existence of a maximum for the enhancement of the far-field heat transfer between deep-subwavelength membranes of SiC. Using fluctuational electrodynamics, we show that the thermal conductance reaches a peak exceeding the blackbody limit by 460 times for 50-nm-thick membranes of SiC at 200 K. This enhancement is driven by the interplay of two surface polariton modes, whose combined contributions are optimized at this thickness and temperature. Our finding thus reveals that the tradeoff of two polariton resonances limits the ability of subwavelength polar membranes to enhance thermal radiation.# Summary. An optional shortened abstract.

Physical Review B 111, 195435 (2025)