▎ 摘　　要

In this article, tunable surface plasmon polaritons (SPPs) in graphene-based elliptical waveguides containing gyro-electric layers are investigated. The general structure has an elliptical cross section, where each gyro-electric layer is surrounded by two graphene layers. The DC magnetic bias is applied on the z-axis. By writing Maxwell's equations inside the gyro-electric medium and applying boundary conditions, closed-form general relations are obtained for electromagnetic components of SPP waves. As a special case, a new plasma-based elliptical structure with double-layer graphene is studied in this paper. The figure of merit (FOM) for this waveguide can be varied by changing the magnetostatic bias and the chemical doping. At the frequency of 40 THz, the FOM of 139 for this waveguide is reported for the B = 1 T and mu(c) = 0.9 eV. Ability to adjust and tune the propagating properties of SPPs in hybrid graphene-plasma elliptical structures can be exploited for the design of new plasmonic components in the THz spectral region.