Enhanced Near-Field Thermal Radiation Driven by Multiple Corner and Edge Modes in Subwavelength Square Nanowires

TL;DR

This study shows that square nanowires exhibit enhanced near-field thermal radiation due to multiple corner and edge resonances, surpassing planar surface mechanisms, with potential applications in nanoscale heat management.

Contribution

It reveals that corner and edge modes dominate thermal radiation in square nanowires, offering a new platform for geometry-controlled heat transfer at the nanoscale.

Findings

Resonances lie within the SiC Reststrahlen band.

Four-fold enhancement of thermal conductance observed.

Maximum enhancement occurs when gap matches nanowire thickness.

Abstract

We demonstrate that the near-field thermal radiation between subwavelength SiC nanowires with square cross sections is dominated by multiple corner and edge resonances rather than the single surface-phonon-polariton channel of planar surfaces. Fluctuational electrodynamics simulations reveal that these resonances lie within the SiC Reststrahlen band, redshift for thinner nanowires, and yield a four-fold enhancement of thermal conductance. This maximum enhancement occurs when the separation gap nearly matches the nanowire thickness, balancing dimensional confinement and interwire coupling. These findings establish square nanowires as a versatile platform for geometrycontrolled near-field heat transfer in nanoscale heat management and energy conversion.