Ultra-Broadband Super-Planckian Radiative Heat Transfer with Artificial Continuum Cavity States in Patterned Hyperbolic Metamaterial

TL;DR

This paper demonstrates that patterned hyperbolic metamaterials can achieve ultra-broadband super-Planckian radiative heat transfer by creating artificial continuum states that extend beyond the light cone, enabling enhanced nanoscale thermal management.

Contribution

The study introduces a novel design of patterned hyperbolic metamaterials that significantly enhances radiative heat transfer through artificial continuum states, surpassing traditional limits.

Findings

Achieves ultra-broadband super-Planckian RHT with patterned HMM.

Utilizes high effective index and anisotropic isofrequency contours of HMM.

Extends radiative heat transfer beyond light cone at nanoscale gaps.

Abstract

Localized cavity resonances due to nanostructures at material surfaces can greatly enhance radiative heat transfer (RHT) between two closely placed bodies owing to stretching of cavity states in momentum space beyond light line. Based on such understanding, we numerically demonstrate the possibility of ultra-broadband super-Planckian RHT between two plates patterned with trapezoidal-shaped hyperbolic metamaterial (HMM) arrays. The phenomenon is rooted not only in HMM's high effective index for creating sub-wavelength resonators, but also its extremely anisotropic isofrequency contour. The two properties enable one to create photonic bands with a high spectral density to populate a desired thermal radiation window. At sub-micron gap sizes between such two plates, the artificial continuum states extend outside light cone, tremendously increasing overall RHT. Our study reveals that structured HMM offers unprecedented potential in achieving a controllable super-Planckian radiative heat transfer for thermal management at nanoscale.