Grounded Graphene-Based Nano-Waveguide with Chiral Cover and Substrate: New Theoretical Investigation

In this paper, we propose a new analytical model for grounded chiral slab waveguides covered with graphene sheets. The general waveguide is constructed of a graphene sheet sandwiched between two different chiral layers (as substrate and cover layers). The substrate is supposed to be a perfect electromagnetic conductor (PEMC), which is able to easily convert to a perfect electric conductor (PEC) or a perfect magnetic conductor (PMC). A novel matrix representation is obtained for the general structure to find its dispersion relation and other propagating parameters. To show the richness of the proposed waveguide, two new structures have been introduced and investigated. It has been shown that the modal properties of these exemplary structures are tunable by changing the chemical potential of the graphene and the chirality. The proposed general structure and its analytical model can be utilized for designing tunable plasmonic devices in THz frequencies.