Rotation-induced significant modulation of near-field radiative heat transfer between hyperbolic nanoparticles

TL;DR

This paper demonstrates that rotating anisotropic nanoparticles can significantly modulate near-field radiative heat transfer, with MoO3 particles achieving up to 12000-fold modulation, offering new control methods for heat transfer at the nanoscale.

Contribution

It introduces a novel approach to modulate near-field radiative heat transfer using particle rotation, especially highlighting the large modulation in MoO3 nanoparticles due to hyperbolic phonon polaritons.

Findings

MoO3 nanoparticles achieve a modulation factor of ~12000.

hBN nanoparticles have a modulation factor of 5.9.

Rotation affects excitation of hyperbolic phonon polaritons.

Abstract

Modulation of near-field radiative heat transfer (NFRHT) with rotated anisotropic hBN and MoO3 nanoparticles (NPs) are investigated. The spectral heat power, total heat power and electric field energy density are calculated at different particle orientations. Numerical results show that the modulation factor of the MoO3 NPs could be up to ~12000 with particle radius of 40 nm at a gap distance of 200 nm, which is ~ 10-fold larger than the state of the art. Excitation of localized hyperbolic phonon polaritons (LHPPs) in different particle orientations allow for the excellent modulation. The modulation factor of the hBN NPs is 5.9 due to the insensitivity of the LHPPs in the type II hyperbolic band to the particle orientations. This work not only provides a new method to modulate NFRHT in particle systems, but also paves the way to explore radiative heat transfer characteristics of anisotropic media.