Strong slow-light effect for a hexagonal graphene coupled metasurface in terahertz

Abstract Exploring higher group index has great benefits in the application of plasmonic slow-light devices. A hexagonal graphene coupled metasurface is proposed for realizing dual plasma induced transparency(dual-PIT) in terahertz through finite-difference time-domain (FDTD) method. The results show that dual-PIT can be effectively tuned by Fermi levels, carrier mobilities, and polarization angles. Moreover, the group index can be as high as ~ 2553. These results may pave the way for the design of slow-light devices.