Tailoring near-field thermal radiation via coupled plasmon-phonon polaritons in n-InAs/hBN stacks

Abstract

Near-field radiative heat transfer (NFRHT) provides a powerful route to surpass the blackbody radiation limit by exploiting surface polaritonic modes in nanostructured materials. We propose and analyze a reconfigurable platform for tailoring NFRHT using coupled plasmon-phonon polaritons sustained by n-doped indium arsenide (n-InAs)/hexagonal boron nitride (hBN) heterostructures. Within the hBN reststrahlen bands, the spectral heat flux shows narrow high-Q peaks locked to the hyperbolic phonon polariton branches. Increasing the carrier density in n-InAs greatly boosts these peaks with a minimal frequency shift, indicating that hyperbolic phonon polaritons set the resonance while plasmons mainly enhance coupling. Momentum-resolved maps of the photon-transmission coefficient reveal iso-frequency contours that evolve from quasi-isotropic rings at zero field to anisotropic lobes with higher doping. Introducing a modest in-plane magnetic field B skews these contours, breaks the k_x → − symmetry, and funnels energy into preferred quadrants, thereby enabling reversible, nonreciprocal heat routing that complements carrier-density control. Our findings highlight a versatile approach to tailoring thermal radiation in planar systems, paving the way for advanced applications in thermal management, energy harvesting and nanoscale optoelectronic devices.