Nano‐scale multifunctional logic gate based on graphene/hexagonal boron nitride plasmonic waveguides

The concept and analysis of a nano-scale multifunctional logic gate based on graphene/hexagonal boron nitride (h-BN) plasmonic waveguides at a wavelength of 7.5µm are presented. By using graphene as a metamaterial with outstanding electro-optical properties, various logical operations including AND, OR, and XOR are implemented. The proposed multifunctional structure supports surface plasmons (SPs) whose dispersion properties can be controlled by applying an electrical field to graphene. The effects of the incident polarisation and the substrate of graphene on the transmission of SPs are investigated. Simulations by finite difference time domain method show that the extinction ratios for the presented logical operations are higher than 15dB. Also, the structure has a compact footprint of 1.12µm2 which is suitable for using in integrated photonic circuits. This provides a path for the development of novel nano-scale practical on-chip applications such as plasmonic memory devices.