A tunable metamaterial based on plasmon-induced transparency effect

Abstract

A Dirac semimetal-based metamaterial is proposed and numerically investigated. A transmission peak is achieved (71.5% amplitude, at resonance frequency 1.22 THz) based on plasmon-induced transparency effect (PIT) between Dirac semimetal strips. This PIT effect is excited by hybridization coupling of bright modes. This transmission peak is enhanced by adjusting horizontal or vertical distances between Dirac semimetal strips. Meanwhile, the resonance intensity and frequency of this PIT effect can be tuned through electrical regulation method (varying the Fermi energy). Moreover, magnetic field regulation method can also be applied in controlling the PIT effect (the direction of magnetic field is parallel or perpendicular). This PIT effect is sensitive to the refractive index of environmental medium. Correspondingly, the phase delay and group delay are also controlled through changing the Fermi energy of Dirac semimetal strips. This proposed PIT tunable metamaterial can be applied in switching, sensing, or other THz devices.