Superlattice bilayer metasurfaces simultaneously supporting electric and magnetic Fano resonances

In this paper, we demonstrated a Fano resonant superlattice metasurface structure composed of bilayer trimeric metallic stripes in each unit cell. It can simultaneously support two types of Fano resonances, which individually possesses electric and magnetic properties at microwave frequencies, respectively. The electric Fano resonance is generated by the anti-phase electric mode interfering with in-phase electric mode, while the magnetic Fano resonance stems from the interference between the magnetic modes in the gap area and the anti-phase electric mode in each layer of the bilayer metasurface. In addition, the double Fano resonances are readily tunable by adjusting a variety of distance degrees of freedom in the composite structure. Our proposed model not only provides a possibility to stimulate and control electric and magnetic Fano resonances simultaneously for microwaves, but also holds great potential for biosensing and switching applications for even higher frequency range such as terahertz or optical region.