Tunability of Plasmon Modes at Uniaxial Chiral–Black Phosphorus Planar Structure

The present study carries out a numerical analysis of uniaxial chiral–black phosphorus at planar structure to investigate the novel traits of plasmon modes. The extended electromagnetic (EM) wave theory is utilized to solve the numerical calculations, and impedance boundary conditions at \(x=0\) $x=0$ are applied to obtain the characteristic equation. The influence of different electron doping, numbers of black phosphorus layers, and chirality values on normalized propagation constant are analyzed for the conductivity of black phosphorus along the armchair (ac) and zigzag (zz) directions. Furthermore, plasmon modes for three kinds of uniaxial chiral medium i.e., \({\varepsilon }_{z}>{\varepsilon }_{t}\) ${\epsilon }_z>{\epsilon }_t$ , \({\varepsilon }_{t}>{\varepsilon }_{z}\) ${\epsilon }_t>{\epsilon }_z$ , and \({\varepsilon }_{t}<1 \text{and}{ \varepsilon }_{z}<1\) ${\epsilon }_t<1\text{and}{\epsilon }_z<1$ are analyzed. Numerical results revealed that black phosphorus and uniaxial chiral features can be used to modulate the plasmon mode in the proposed frequency range. It is concluded that \({\varepsilon }_{t}>{\varepsilon }_{z}\) ${\epsilon }_t>{\epsilon }_z$ support at very high frequencies as compared to the other two cases. The presented study may be useful to fabricate black phosphorus-based nanophotonic devices.