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

Abstract

Modulation of near-field radiative heat transfer (NFRHT) with rotated anisotropic hBN and α-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 α-MoO3 NPs could be up to ∼12,000 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 might be helpful in designing a high performance near-field radiative modulator in particle systems.