▎ 摘　　要

It is necessary to explore the potential applications of surface plasmon polaritons (SPPs) on graphene metasurfaces and enhance the performance of their on-off modulators and slow-light effect. A simple monolayer graphene metasurface is developed for achieving the plasmon-induced transparency (PIT) phenomenon in the terahertz range. PIT can be effectively tuned by the positional parameter, the Fermi level, and the carrier mobility using the finite-difference time-domain (FDTD). Moreover, it is found that a quad-frequency on-off modulator and an outstanding slow-light effect can be realized in this proposed metasurface. Interestingly, modulation depth (MD), insertion loss (IL), Delta T, and the group index are of 98.90%, approximate to 0.05 dB, 0.97, and 3383, respectively. Hence, the results show that the proposed metasurface has excellent performance for on-off modulators and a slow-light effect, which can provide theoretical guidance for designing terahertz micro-nanophotonic devices.