Versatile Tunable Terahertz Absorption Device Based on Bulk Dirac Semimetals and Graphene

We employed the CST Microwave Studio software 2020 and the FDID algorithm for simulation. We have designed a terahertz broadband absorber based on Dirac semimetals and graphene, achieving continuous broadband absorption with a rate exceeding 80% over the range from 7.6776 to 9.172 THz. This broadband absorber features two independent tuning modes, utilizing graphene and Dirac semimetals, and exhibits strong electromagnetic adaptability. Furthermore, we conducted an in-depth analysis of the physical mechanisms underlying the high absorption in these absorbers using impedance matching theory and localized surface plasmon resonance (LSPR) theory. Variations in the dielectric constants of different dielectric layers and the relaxation time of graphene can also modulate the absorption rate. In summary, our proposed terahertz broadband absorber, employing two distinct tunable materials, enhances the device's flexibility and environmental adaptability, offering promising prospects for wideband absorption applications.