A bi-tunable switchable polarization-independent dual-band metamaterial terahertz absorber using VO2 and Dirac semimetal

•A bi-tunable switchable dual-band absorber based on vanadium dioxide and Dirac semimetal films metamaterial is proposed in the terahertz range.•The proposed absorber shows two available pathways to achieve the tunability of its operating frequency and response intensity.•Two perfect absorption peaks exhibit polarization independent characteristic and have a wide incident angle tolerance. 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.