Analogue of tunable electromagnetically induced transparency in terahertz metal-graphene metamaterial

In this paper, a novel EIT analogue consisting of metal-based resonator integrated with graphene is proposed, which can achieve tunable EIT-like effects in terahertz frequencies. For practical applications, a thin Si layer is grown on the resonator to provide a flat surface to transfer monolayer graphene using a wet transfer method. Numerical and theoretical investigations on the tunable EIT-like effect are carried out. The simulations reveal that EIT-like phenomenon is induced by coupling of bright-dark mode of metal-based resonator. Further investigations reveal that the amplitude of EIT window could be modulated by changing the Fermi level of graphene meanwhile the resonant frequencies exhibits slight shift. The physical mechanism underling the modulation phenomenon is mainly attributed to the damping rate of the dark mode and bright mode resonators, which is verified by theoretical analysis of classical two-particle model and absorption of proposed EIT-like analogue. The retrieved effective permittivity and permeability of the proposed metamaterial cell clearly exhibit dispersion in dependence of Fermi level of graphene. This work will offer a new perspective application in terahertz modulation and slow light devices.