Applications based on dynamically plasmon-induced transparency in bilayer borophene metamaterials structure

This paper proposes a tunable plasma-induced transparency (PIT) metamaterial structure based on a bi-layer borophene structure. The main structure is composed of upper borophene strips and lower double ellipses. The coupling mode theory (CMT) is used to fit the PIT spectrum, and the finite difference time domain (FDTD) results fit well with the theory. The influence of geometric parameters (including the size of the borophene strip, the major, minor axes of the ellipse, and the coupling distance between the two substructures) on the transmission spectrum is studied. Besides, the transmission window can be tuned by controlling the borophene electron density, and a modulation depth of 93.9% between the "on" and "off" states is achieved. Additionally, this borophene structure exhibits excellent slow-light performance (group index of 183.56) and sensing capabilities (refractive index sensitivity and Figure of Merit (FOM) are about of 28.03THz/RIU,75.82RIU-1). This indicates that this borophene metamaterial structure offers a new platform for manufacturing optical modulators, slow-light devices, and terahertz sensors.