Spectrally enhancing near-field radiative heat transfer by exciting magnetic polariton in SiC gratings

TL;DR

This paper theoretically demonstrates that magnetic polaritons can significantly enhance near-field radiative heat transfer between SiC gratings, revealing new control mechanisms for thermal radiation at the micro and nanoscale.

Contribution

It introduces the first theoretical demonstration of magnetic polariton excitation enhancing near-field radiative heat transfer in SiC gratings.

Findings

Magnetic polariton causes an additional spectral heat flux peak.

Near-field heat transfer is significantly enhanced by magnetic resonance.

Interplay between magnetic polariton and surface phonon polaritons is elucidated.

Abstract

In the present work, we theoretically demonstrate, for the first time, that near field radiative transport between 1D periodic grating microstructures separated by subwavelength vacuum gaps can be significantly enhanced by exciting magnetic resonance or polariton. Fluctuational electrodynamics that incorporates scattering matrix theory with rigorous coupled wave analysis is employed to exactly calculate the near field radiative heat flux between two SiC gratings. Besides the well known coupled surface phonon polaritons (SPhP), an additional spectral radiative heat flux peak, which is due to magnetic polariton, is found within the phonon absorption band of SiC. The mechanisms, behaviors and interplays between magnetic polariton, coupled SPhP, single interface SPhP, and Wood's anomaly in the near field radiative transport are elucidated in detail. The findings will open up a new way to control near field radiative heat transfer by magnetic resonance with micro or nanostructured metamaterials.