Tunable electromagnetically induced reflection with a high Q factor in complementary Dirac semimetal metamaterials

We demonstrate a tunable electromagnetically induced reflection (EIR) effect with a high Q factor based on a complementary bulk Dirac semimetal (BDS) metamaterial structure in the terahertz region. The proposed design is composed of wire-slot and split-ring resonator slot structures, which serve as radiative and subradiative elements, respectively. Destructive interference between the two elements gives rise to a reflection peak with a high Q factor (~87.6), enabling sensitive terahertz sensing, in which the sensitivity of the proposed BDS sensor is 302.5 GHz per refractive index unit, and the figure of merit value is ~19. Interestingly, the EIR window in the BDS metamaterial structure can be dynamically controlled by changing the Fermi energy without reoptimizing the structural parameters. Therefore, our work may open up the possibility for various terahertz functional devices, such as tunable sensors and switches.