Simultaneous switching at multiple frequencies and triple plasmon-induced transparency in multilayer patterned graphene-based terahertz metamaterial

A novel multilayer terahertz metamaterial composed of double rectangle, vertical single rectangle, vertical double rectangle and single rectangle graphene layer is proposed. The dynamic adjustable triple plasmon induced transparency (PIT) is realized by coupling two bright modes and two dark modes, which is an especial synergy effect between two single-PIT. Coupled mode theory contained four resonators is employed to explain the triple-PIT, and the theoretical results exhibit excellent consistency with finite-difference time-domain. Surprisingly, the triple-PIT can evolve into a dual-PIT or a single-PIT only by changing the Fermi level of graphene, and the amplitude modulation degrees at the four resonance frequencies of the triple-PIT are 74.7%, 87.8%, 76.5%, and 77.7%, respectively. In addition, a simultaneous switching at multiple frequencies is realized by adjusting different Fermi levels. Therefore, this study not only lays the foundation for explaining phenomenon of the triple-PIT but also puts forward new ideas for the design of optoelectronic device.