Graphene metasurface for broadband, wide-angle and polarization-insensitive carpet cloak

Although great progress has been made in stealth research based on metamaterial/metasurface, it is still a great challenge to achieve broadband, wide-angle and full polarization stealth at the same time. In this paper, a metasurface carpet cloak based on graphene rings is proposed to address this issue. Simulation results demonstrate that the arched carpet cloak can achieve a polarization-insensitive invisibility with a large working bandwidth of 45% and a wide angular span of +/- 40 degrees in terahertz range. The cloaking bandwidth can be further increased to 60% by adjusting graphene Fermi energy to control the phase dispersion of meta-atoms. By comparing the arched and triangular carpet cloaks and the arched carpet cloaks with different curvature, the sensitivity of cloaking performance to the shape of carpet cloak is demonstrated. The metasurface based on graphene ring can not only give a good solution for broadband, wide-angle and polarization-insensitive invisibility in terahertz to mid-infrared region, but also provide inspiration for the construction of other metasurface devices with excellent performance.