Achieving Three-band Absorption and Broadband Polarization Conversion Dual-functional Metamaterial Based on Vanadium Dioxide and Bulk Dirac Semimetals

In this paper, we present a novel design that can realize a three-band absorber and a high-efficient polarization converter. And it is functional switch through the phase transition of vanadium dioxide (VO2) and adjusting the Fermi energy of Dirac Semimetals (BDs). When the Fermi energy is 60 meV and VO2 is insluting state, it behaves a three-band absorber and the theoretical analysis shows that three peaks absorption reaches 88.3%, 99.2%, and 84.9% at 3.30 THz, 6.15 THz and 8.72 THz. When the Fermi energy is 200 meV and VO2 is metallic state, the metamaterial act as linear polarization converter. It can realize over 90% high-efficiency polarization conversion radios of y-linearly polarized waves in the 7.37-8.85 THz frequency range. In addition, the physical mechanisms of the two functions based on our design are debated. The metamaterial proposed has potential applications in biological sensing, imaging and wireless communication.