Multifunctional Vanadium Dioxide–Stabilized Graphene–Graphite Metasurface for Terahertz Waves

A wideband terahertz (THz) metasurface absorber integrating layered graphene, graphite, and vanadium dioxide (VO2) is proposed, demonstrating multifunctional shielding and polarization control. The multilayer stack alternates graphite ground planes with SiO2spacers, ensuring impedance matching and dynamic EM response. Graphite provides high conductivity, anisotropy, and thermal stability, serving as a lightweight alternative to metals that enhances broadband absorption and reduces ohmic losses. VO2, a phase-change material, transitions from insulating to metallic above$67~^{\circ }$C, imparting robustness against thermal fluctuations and enabling passive spectral reconfigurability. In the insulating state, absorptance exceeds 90% across 2.17–6.95 THz with shielding effectiveness (SE) above 47 dB, while in the metallic state absorptance remains >90% with SE beyond 20 dB. This high attenuation, quantified by SE surpassing 47 dB in the insulating phase and 20 dB in the metallic phase, underscores suitability for electromagnetic interference (EMI) protection. The metasurface remains polarization-insensitive under TE/TM excitations and oblique incidence, with ADS circuit modeling closely matching CST simulations. Its compact design and feasible fabrication pathways support experimental viability, establishing a reproducible multifunctional platform for THz shielding, polarization control, and plasma-assisted device integration in next-generation communication systems.