The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 25 4 2026 02 20 Tunable broadband perfect absorber based on Graphene Tunable broadband perfect absorber based on Graphene 465 469 3711 10.47176/ijpr.25.4.12280 FA Ramin Joudi Department of Physics, University of Zanjan, Iran Mojtaba Nasiri Department of Physics, University of Zanjan, Iran 0000-0003-2208-8528 Ebrahim Madadi Faculty of Engineering Sciences and Engineering Physics, Buin Zahra Journal Article 2025 08 07 In this paper a graphene-based metasurface is designed and analyzed to operate as an electromagnetic wave absorber in the terahertz frequency range. The proposed geometrical structure consists of a graphene ring with four slits in each unit cell, arranged in a two-dimensional array on a dielectric substrate. Simulation results obtained using the finite element method (FEM) demonstrate that, by tuning the geometric and physical parameters of the structure—such as the slit width inner and outer radii of the ring and the Fermi energy of graphene—the absorption of electromagnetic waves can be significantly enhanced over a specific frequency range. This high absorption performance is attributed to the excitation of surface plasmon resonances in graphene as well as the induced magnetic resonance modes within the ring structure. The proposed design offers high tunability and fabrication simplicity, making it a promising candidate for applications in terahertz sensing tunable absorbers and stealth technologies. In this paper a graphene-based metasurface is designed and analyzed to operate as an electromagnetic wave absorber in the terahertz frequency range. The proposed geometrical structure consists of a graphene ring with four slits in each unit cell, arranged in a two-dimensional array on a dielectric substrate. Simulation results obtained using the finite element method (FEM) demonstrate that, by tuning the geometric and physical parameters of the structure—such as the slit width inner and outer radii of the ring and the Fermi energy of graphene—the absorption of electromagnetic waves can be significantly enhanced over a specific frequency range. This high absorption performance is attributed to the excitation of surface plasmon resonances in graphene as well as the induced magnetic resonance modes within the ring structure. The proposed design offers high tunability and fabrication simplicity, making it a promising candidate for applications in terahertz sensing tunable absorbers and stealth technologies. https://ijpr.iut.ac.ir/article_3711_aba18772fc70c8cbf79a79f413ef102b.pdf