Tunable anisotropic plasmon-induced transparency in black phosphorus-based metamaterials

Black phosphorus (BP), as a new type of two-dimensional material, has drawn considerable interest because of its distinct physics and electronic characteristics. In this work, we theoretically present a BP-based metamaterial, unit cell of which is composed of a rectangular BP nano-patch and two parallel BP strips. The research results indicate that tunable anisotropic plasmon-induced transparency (PIT) effect can be achieved in the presented metamaterials when the polarization of incident light is along armchair and zigzag directions of BP crystal, respectively. Moreover, the spectra responses and group delay accompanied by the PIT effect can be actively controlled by adjusting the carrier density and geometric parameters. The electromagnetic simulation results calculated by finite-difference time-domain (FDTD) method show good agreement with the coupled Lorentz oscillator model. Our proposed nanostructure provides a new path for designing photonic devices such as slow light and photodetector in the mid-infrared region.