Switching of electromagnetically induced transparency and absorption of graphene metastructure with the three resonators

Abstract

A graphene metastructure (GMST) with switching features from electromagnetically induced transparency (EIT) and absorption (EIA) is theoretically proposed in a three-resonator system by controlling the Fermi energy (Ef) of the graphene in the terahertz (THz) regime. When Ef = 0.9 eV, the graphene has less influence on the lower EIT metastructure, and the EIT phenomenon of the three-resonator metastructure is realized. The EIT transmission window appears between 0.763 and 0.965 THz, and at 0.803 THz, the transmission peak reaches 0.860. When Ef = 0.12 eV, graphene is weakly coupled to the substructure, thus constructive interference between the three resonators generates a magnetic dipole that strongly traps the incident magnetic energy, thus contributing to the EIA phenomenon. The absorption window appears between 0.650 and 0.902 THz. The frequency point of the absorption peak of the EIA phenomenon at this time coincides perfectly with the frequency point of the transmission peak of EIT at Ef = 0.9 eV, both at 0.803 THz. The working principle of this GMST is explained through the surface current distribution. To reproduce EIT and EIA, the two oscillator model is used and the simulation results are proved to be consistent and valid. The structural parameters are also discussed and the properties of the GMST are explored.

KEYWORDS:

• Electromagnetically induced transparency
• electromagnetic induced absorption
• graphene
• metastructure
• two-oscillator model

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by College Student Innovation Training Program of Nanjing University of Posts and Telecommunications.