Quad-functional narrowband-broadband electrical/thermal dual-controlled adjustable metasurface absorber

Abstract

This study presents a novel terahertz metamaterial absorber that utilizes the adjustable properties of vanadium dioxide and graphene to dynamically alter its functions and absorption bands. The finite-difference time-domain (FDTD) modelling results show that the suggested design can effectively absorb a wide range of frequencies and two narrow bands at the same time. The absorption frequency of the QMA can be change by controlling the chemical potential of graphene and the temperature of VO₂. The QMA show switchable character between narrowband absorption mode “NAM” and broadband absorption mode “BAM” by electronically varying the chemical potential of graphene, it can be seen in P₁ and P₂ at frequency 2.79 and 3.33 THz respectively. Thermal modification of VO₂ phase shift allows the low-frequency absorption mode (“LAM”) and the high-frequency absorption mode (“HAM”) to transition between P₃ and P₄, which correspond to frequencies of 3.53 and 4.43 THz, respectively. The mechanism of “NAM” and “BAM” is found to be the transition between the fundamental and second order graphene surface resonances, whereas the phase change in VO₂ is responsible for the transition between “LAM” and “HAM”. Furthermore, the QMA is polarization independent in all absorption modes. These results imply that the suggested QMA has a great deal of promise for use in sensing, filtering, switching and stealth applications.