Supplementary Material

FIG. S1. Absorption spectra of the VSC mode at different Fermi levels of the lower graphene sheet. The black lines represent the frequencies of the VP modes calculated using the CCOM. Moreover, the LGPR frequencies (red line) and the molecular vibrations (white lines) are given. The relevant structural parameters are d = 1.0 μm, w = 31 nm, Λ = 150 nm, and t = 5 nm.