A Broadband Switchable Metamaterial Absorber/Reflector Based On Multi-Laps Graphene Sheets in the Terahertz Band

Switchable metamaterial absorbers/reflectors (MAs/MRs) are important bifunctional electromagnetic devices and have been the subject of numerous scientific studies. However, there is a lack that operate in terahertz band. Here, we theoretically propose broadband switchable MA with many excellent properties, such as good thermal stability, high insensitivity to inferior film quality graphene, excitation polarization wide incident angles, outstanding structural parameter tolerance. The bandwidth proposed 3.4 THz an absorptivity over 90% frequency band 1.6-5 THz. absorber can switch reflector reflectivity 93% by tuning chemical potential graphene reducing temperature. Therefore, switching intensity exceeds 83%. physical mechanisms absorption structure investigated using impedance matching theory multiple reflection interference theory. mechanism discussed analyzing effective parameters. performing detailed numerical calculations analyze surface loss intensity, electric field, magnetic field. These findings accelerate development devices.