Modulation of a dual-band metamaterial absorber in the terahertz band

Abstract

In this paper, a tunable metamaterials absorber with Dirac semimetals and VO2 strips is present in the Terahertz (THz) range. At room temperature, two absorption peaks are revealed at resonance frequencies 10.1 THz (76% amplitude) and 20.3 THz (60% amplitude), respectively. Based on the tunability of these two materials, three modulation strategies are proposed to control the resonant properties of the absorber. As the conductivity increase, three newly absorption peaks (62% amplitude at 19.9 THz, 65% amplitude at 27.7 THz, and 73% amplitude at 37.3 THz) are achieved due to four VO2 strips undergoing the insulation phase-metal phase changes. The resonant properties of this absorber can be converted due to the conversion function of four VO2 strips. Moreover, both original absorption peaks can be control in the continuous frequency range by increasing the Fermi energy. Finally, the magnetic field external is adopted to modulate the resonant properties of this absorber. Both of the original absorption peaks are increased in a continuous frequency range, and two newly absorption peaks (74% amplitude at 23.9 THz and 60% amplitude at 36 THz) are achieved.