Graphene-based hybrid metasurfaces with quasi-bound states in the continuum for manipulating terahertz absorption

Abstract We present a graphene-based hybrid metasurface with quasi-bound states in the continuum (BICs) for manipulating terahertz (THz) wave absorption. By the strategic application of structural perturbations for the THz metasurface, the symmetry-protected BICs transforms into quasi-BICs. The incorporation of graphene adeptly satisfies the critical coupling condition, thereby facilitating the attainment of the theoretical maximum absorption of 0.5 for the quasi-BICs in the THz region. And the Q-factor of the quasi-BIC can be up to 2755. Moreover, the metasurface exhibits a distinctive ability for unique tuning and efficient absorption of terahertz waves by varying the asymmetry parameter and Fermi levels. This work provides promising strategies for manipulating terahertz wave absorption.