Realization of tunable plasmon-induced transparency by bright-bright mode coupling in Dirac semimetals

A numerical and theoretical study is presented on the realization of the tunable plasmon-induced transparency (PIT) effect in Dirac semimetal films (DSFs) that are known as “three-dimensional graphene”. The weak hybridization between the two parallel bright modes leads to the novel PIT optical response. The properties of the PIT system can be controlled by adjusting the geometric parameters of the DSF strips. Meanwhile, the resonant frequency of the PIT can be dynamically tuned by varying the Fermi energy of the DSFs instead of refabricating the structures. Correspondingly, by adjusting the Fermi energy of the DSFs, a large group delay of more than 1.86 ps is obtained in the vicinity of the transparency peaks. Such proposed DSFs-based PIT system may open up avenues for tunable terahertz switching, slow-light devices, sensing technology and some other THz devices.