A tunable dual-band terahertz hybrid metamaterial absorber based on vanadium oxide (VO2) phase transition

In the study, a tunable dual-band terahertz hybrid metamaterial absorber was designed and explored. The proposed hybrid metamaterial absorber was composed of an Au ring, an Au cross structure and vanadium dioxide (VO2) films incorporated at the four ends of the cross structure. Theoretical simulation results showed that the hybrid metamaterial exhibited dual-frequency resonances. The low-frequency resonance was ascribed to the ring, whereas the high-frequency resonance was ascribed to the cross structure. The resonant frequencies of the hybrid metamaterial absorber could be tuned by changing the effective length of electrically resonant cross structure through triggering the insulator-metal phase transition of the VO2 at the four ends of the cross structure.