Tunable terahertz metamaterial absorber by using graphene for tailoring absorbing performance

Graphene has some unique electric properties. Electric properties of graphene can be adjusted by chemical treatment or electrostatic treatment. Anti-parallel surface current density on cross-shaped sandwich structure and the cumulative charge on gap between unit cell of metamaterial absorber may be adjusted using graphene. The amount of surface current density and amount of cumulative charge on gap between unit cell may affect the magnetization and polarization, respectively. Tailoring magnetization may alter the absorber performance. In this work, we propose terahertz tunable metamaterial absorber by using graphene. The shifting of absorbance peak frequency altered from 0.77 THz to 0.65 THz while Fermi energy was increasing. The absorbance peak for 10 meV, 100 meV, 200 meV, 300 meV and 400 meV of Fermi energy are 0.72, 0.79, 0.87, 0.92 and 0.94, respectively. The alteration of electric properties of graphene yields alteration of absorbance peak and shifting of absorbance peak frequency. (paper)