Metasurfaces Assisted Twisted α-MoO3 for Spinning Thermal Radiation

Abstract

Spinning thermal radiation has demonstrated applications in engineering, such as radiation detection and biosensing. In this paper, we propose a new spin thermal radiation emitter composed of the twisted bilayer α-MoO3 metasurface; in our study, it provided more degrees of freedom to control circular dichroism by artificially modifying the filling factor of the metasurface. In addition, circular dichroism was significantly enhanced by introducing a new degree of freedom (filling factor), with a value that could reach 0.9. Strong-spin thermal radiation resulted from the polarization conversion of circularly polarized waves using the α-MoO3 metasurface and selective transmission of linearly polarized waves by the substrate. This allowed for extra flexible control of spinning thermal radiation and significantly enhanced circular dichroism, which promises applications in biosensing and radiation detection. As a result of their unique properties, hyperbolic materials have applications not only in spin thermal radiation, but also in areas such as near-field thermal radiation. In this study, hyperbolic materials were combined with metasurfaces to offer a new idea regarding modulating near-field radiative heat transfer.

Strong spinning thermal radiation enabled by germanium-based chiral dielectric metasurface

“…Using spin angular momentum facilitates the engineering of spin-dependent nanoscale interactions between light and matter. Recent studies involving chiral structures have further extended this exploration, showcasing the feasibility of spin thermal radiation for engineering applications, including thermal detection [16][17][18][19].…”

A polarization-dependent perfect absorber with high Q-factors enabled by Tamm phonon polaritons in hyperbolic materials

“…[35][36][37] Recently, an emerging two-dimensional van der Waals (vdW) material, denoted as a-phase molybdenum trioxide (a-MoO 3 ), has garnered substantial attention due to its exceptional characteristics of high anisotropy and inherent capability to support hyperbolic polaritons. [38][39][40][41][42][43][44] As an excellent natural biaxial hyperbolic material, a-MoO 3 has three distinct reststrahlen bands (RBs) aligned with different crystal axes, enabling effortless achievement of in-plane anisotropy. In addition, a-MoO 3 exhibits exceptional hyperbolic phonon polarization characteristics and demonstrates significant confinement of electromagnetic fields within the mid-infrared spectrum.…”

Magnetical Manipulation of Hyperbolic Phonon Polaritons in Twisted Double-Layers of Molybdenum Trioxide

“…Strongly anisotropic materials can support hyperbolic phonon polaritons (HPhPs) that exhibit a hyperbolic dispersion whose permittivity tensor posses both positive and negative principal components [ 2 , 7 , 8 , 9 ]. There has been significant progress in natural vdW crystal and heterostructures, which are characterized by an anisotropic polaritonic response, leading to elliptical, hyperbolic, or biaxial polaritonic dispersions [ 10 , 11 ]. Different polaritonic modes in vdW materials have been discovered, such as plasmon polaritons in graphene, exciton polaritons in molybdenum diselenide ( ), phonon polaritons in hexagonal boron nitride (hBN), and [ 12 , 13 , 14 , 15 , 16 ].…”