A bi-tunable switchable polarization-independent dual-band metamaterial terahertz absorber using VO2 and Dirac semimetal
Tongling Wang, Huiyun Zhang, Yuping Zhang, Maoyong Cao
Abstract
A bi-tunable switchable dual-band THz absorber using vanadium dioxide (VO2) and Dirac semimetal films (DSFs), which is independent on polarization, is proposed. The frequency and intensity of absorptances of the two absorption peaks can be dynamically changed by tuning the Fermi energy of the DSF or the VO2 conductivity. Moreover, the absorber can alternate between an absorption function (with an absorptance of 99.4%) and a reflection function (with a reflectance of 77.4%) at the frequencies of absorption peak B in case of VO2 transitions from metallic state to insulator state. In addition, the proposed absorber exhibits advantages such as polarization-independent nature and wide incident angle tolerance. This study provides references to future studies of THz bi-tunable dual-band or multi-band polarization-independent absorbers.