Dual-controlled tunable absorber using a hybrid Dirac semimetal–strontium titanate metamaterial
Baojing Hu, Ming Huang, Yang Li, Jinyan Zhao
Abstract
A dual-controlled tunable polarization-independent perfect absorber based on bulk Dirac semimetal (BDS) and strontium titanate (STO) is proposed and analyzed. The results show that the absorptivity can reach 99% at 1.26 THz due to the critical coupling effect. Meanwhile, the absorptivity and resonant frequency of the proposed absorber can be dual-tuned dynamically by varying the temperature of the STO and the Fermi energy of the BDS. Furthermore, the coupled mode theory (CMT) and the equivalent circuit model (ECM) are used to theoretically analyze the performance of the absorber. Finally, modulation of the absorptivity spectra by tailoring the structure dimensions is also discussed. This work provides potential applications in the design of dual-tunable filters and absorbers.