Electric and magnetic surface polariton mediated near-field radiative heat transfer between metamaterials made of silicon carbide particles

Abstract

Near-field radiative heat transfer between isotropic, dielectric-based metamaterials is analyzed. A potassium bromide host medium comprised of silicon carbide (SiC) spheres with a volume filling fraction of 0.4 is considered for the metamaterial. The relative electric permittivity and relative magnetic permeability of the metamaterial are modeled via the Clausius-Mossotti relations linking the macroscopic response of the medium with the polarizabilities of the spheres. We show for the first time that electric and magnetic surface polariton (SP) mediated near-field radiative heat transfer occurs between dielectric-based structures. Magnetic SPs, existing in TE polarization, are physically due to strong magnetic dipole resonances of the spheres. We find that spherical inclusions with radii of 1 μm (or greater) are needed in order to induce SPs in TE polarization. On the other hand, electric SPs existing in TM polarization are generated by surface modes of the spheres, and are thus almost insensitive to the size of the inclusions. We estimate that the total heat flux around SP resonance for the metamaterial comprised of SiC spheres with radii of 1 μm is about 35% greater than the flux predicted between two bulks of SiC, where only surface phonon-polaritons in TM polarization are excited. The results presented in this work show that the near-field thermal spectrum can be engineered via dielectric-based metamaterials, which is crucial in many emerging technologies, such as in nanoscale-gap thermophotovoltaic power generation.

Hyperbolic Metamaterials as an Analog of a Blackbody in the Near Field

“…With today's nanofabrication techniques it is possible to manufacture artificial materials such as photonic band gap materials and metamaterials which exhibit very unusual material properties like negative refraction [23]. Due to such properties they are considered as good candidates for perfect lensing [24,25], for repulsive Casimir forces [26][27][28][29] and enhanced or tunable radiative heat flux at the nanoscale [18][19][20][30][31][32] to mention a few.There exists a class of uniaxial metamaterials for which the permittivity and permeability tensor elements are not all of the same sign [33]. In particular, for such materials the dispersion relation for the solutions of Helmholtz's equation inside the material is not an ellipsoid as for normal uniaxial materials [34] but a hyperboloid [35].…”

“…The common paradigm is that the largest heat flux can be achieved when the materials support surface polaritons which will give a resonant energy transfer restricted to a small frequency band around the surface mode resonance frequency [3,4,12,13]. Many researchers have tried to find materials enhancing the nanoscale heat flux due to the contribution of the coupled surface modes by using layered materials [14,15], doped silicon [16,17], metamaterials [18][19][20], phase-change materials [21] and recently graphene [22].…”

Near-field thermal electromagnetic transport: An overview

“…Figure 5 shows the temperature of sphere B as a function of time for both the resonant and non-resonant dielectric functions, and in the absence and presence of sphere C. For the calculations, the net heat rate Q net,in is integrated over a bandwidth of 0.02 eV. The analysis presented in this section could be extended to multiple spheres, which is important in the design of Mie resonance-based metamaterials for controlling thermal emission [61,68,69] and for understanding heating and cooling by near-field thermal radiation.…”

Thermal Radiative Wavelength Selectivity of Nanostructured Layered Media

“…Optical properties of materials doped with nanoparticles have been investigated before [12,13]. Experimental and analytical study of thermal coatings doped with nanoparticles such as Gonome et al [14,15] can also be found in literature.…”