Dual-band Electromagnetically Induced Transparency Terahertz Metamaterial Based on U-like Resonator and Metallic Cut Wire for Sensing Application

In this paper, a new scheme for dual-band terahertz electromagnetically induced transparency (EIT) is reported using a simple metamaterial structure, whose surface structure is composed of periodically arranged U-like resonator and metallic cut wire. Two EIT peaks located at 0.65 THz and 1.26 THz with an average transmission intensity of greater than 93% are realized, the formation mechanism of two transparent peaks is mainly attributed to the coupling of bright-bright mode, which is verified by their near-field distributions. Structure parameter changes of metamaterial provide a great ability to regulate and control the performance of two transparent peaks. Interestingly, by replacing the lower baseline of U-like resonator with vanadium dioxide (VO2), the designed metamaterial can dynamically tune the number of EIT peaks. It is revealed that dual-band transparency could be actively converted to single-band transparency by merely varying the properties of VO2 from metallic state to insulating state without changing the structure complexity, and the maximum amplitude modulation depth could reach 93.1%. Further application of designed metamaterial related to sensing is discussed. The designed metamaterial with these excellent features could pave the way for the applications of terahertz technology-related fields.