Competition and coupling of nanoscale radiative and conductive thermal transfer in a fully filled hyperbolic medium
Phys. Rev. B 114, 045410 – Published 8 July, 2026
DOI: https://doi.org/10.1103/r9b4-jwh9
Abstract
Near-field radiative heat transfer (NFRHT) exceeds the blackbody limit through evanescent wave tunneling but faces scalability barriers due to nanoscale vacuum-gap constraints. To overcome this limit, the present study proposes a K-infiltrated nanoporous hyperbolic metamaterial as a functional gap-filling medium. A fully coupled multiphysics framework—integrating fluctuational electrodynamics, conductive transport, and energy-conserving temperature stratification—resolves the radiation-conduction competition within the filler. Crucially, we demonstrate radiation-dominated heat transfer higher than conduction in solid-state systems: with a 100-nm-thick hyperbolic metamaterial filled between two doped silicon plates, radiative flux exceeds vacuum-gap NFRHT by 4 orders of magnitude, and even surpasses thermal conduction at ΔT > 300 K. This breakthrough stems from broadband hyperbolic dispersion and synergistic surface plasmon-hyperbolic polariton coupling, validated via spectral transmission peaks. By replacing vacuum with a bulk solid medium, this work provides a foundational understanding of radiation-conduction competition and electromagnetic mode coupling in nanoscale thermal transport, offering insights relevant to nanophotonics and thermal metamaterial research.
