Switchable Fano Resonance Based on Cut-Induced Asymmetric Split-Ring Resonators with Dirac Semimetal Film

We present cut-induced asymmetric split-ring resonator (CASRR) structure that can achieve switchable Fano resonance based on Dirac semimetals at the terahertz region. By changing the asymmetric geometric parameter from 3 to 13 µm, the transmission spectrum can be switched from single to dual channel and the Fano resonance can be gradually enhanced, which is consistent with the two coupled oscillators model. Meanwhile, the Fano effect can also be effectively switched by adjusting the Fermi energy of Dirac semimetal film (DSF) and it is suitable for practical applications. In the view of sensing application, the sensitivity based on Fano resonance is up to 69.75 GHz/RIU and 134.25 GHz/RIU with the thickness of sample 1 μm and 20 μm, respectively. Such manipulation of Fano resonance by using DSF may have potential applications in terahertz switch, sensor, and multichannel communication.