Dynamically switchable dual-band absorber based on electromagnetically induced reflection in metal-graphene hybrid metamaterial

Abstract

In this paper, a dynamically switchable dual-band absorber based on electromagnetically induced reflection (EIR) in metal-graphene hybrid metamaterial is proposed. The unit cell of metamaterial absorber has three layers. The top layer consists of two split-ring resonators (SRRs) and two orthogonal cut-wires (CWs) with different lengths. Due to the low reflection dips in EIR structure and good absorption of graphene, two absorption bands accompanied with more than 90% absorptions are obtained under y-polarized and x-polarized incident waves, respectively. The power loss densities at the absorption points clearly reveal the absorption positions of the metamaterial absorber. In addition, the electric field, magnetic field and surface current distributions explain the reason of high absorption. According to the surface currents at four resonant points, we draw the schematic diagrams of multipole moments, which are confirmed by multipole scattering theory. The tunable absorption performance of metamaterial absorber can be observed by tuning the Fermi level of graphene. The metamaterial absorber exhibits excellent wide polarization angle behavior and shows great prospects in multi-band metamaterial absorber under oblique incidence. The proposed metamaterial absorber expands the development of metamaterial and shows great potential for multifunctional metamaterial absorber.