Modeling Graphene-Based Plasmonic Waveguides by Mixed FEM With Surface Current Boundary Condition

In this letter, the mixed finite element method (Mixed FEM) incorporating with the surface current boundary condition (SCBC) is firstly proposed to perform eigenmode numerical simulations of graphene-based plasmonic waveguides. The SCBC which is based on modeling graphene as the zero-thickness conductive sheet, is introduced to reduce the extremely fine discretization of graphene at the atomic scale. Thus, enormous unknowns and computational resources are significantly decreased in the proposed new method. Numerical examples of some typical graphene-based waveguides are presented to verify numerical accuracy and computational efficiency of the new method.