High-performance dual-control tunable absorber with switching function and high sensitivity based on Dirac semi-metallic film and vanadium oxide

This study combines two tunable metamaterials, vanadium oxide (VO2) and Dirac semimetal thin films (DSF), to design a tunable multi-band narrowband absorber with on-off switching function. When VO2 is in metallic state, the absorber has three perfect absorption peaks with absorptivity greater than 97%. By lowering the temperature, VO2 can be transformed into an insulating state, which greatly reduces the absorption rate of the absorber and realizes the change of the state of the absorber. We have conducted more in-depth studies on the absorption mechanism and structural parameters of the absorber in the on state. By changing the Fermi level (EF) of the DSF, the resonant frequency of the absorber is tunable up to 0.444 THz while maintaining the absorption rate above 90%. The absorber can maintain a stable working state in various complex electromagnetic environments, and has a refractive index sensitivity (S) of up to 462 GHz/RIU. Due to the advantages of various control methods, good performance and diverse functions, our designed absorber has good practical development prospects and market value in many fields such as switching and detection.