Fig. 5

Dispersion relation in the graphene stack. The blue and red lines are for the ambient medium propagating and evanescent z-directional wavenumber respectively. The green line is the evanescent z-directional wavenumber of the graphene-dielectric stack. The black lines represent the propagating z-directional wavenumber of the graphene-dielectric stack for four different values of chemical potential. The interval I is bounded by the z-directional wavenumbers of the graphene-dielectric stack