Voltage-controlled surface plasmon-polaritons in double graphene layer structures

The spectra and damping of surface plasmon-polaritons (SPPs) in double graphene layer structures are studied. It is proved that SPPs in those structures exhibit an outstanding voltage tunability of velocity and damping, inherent to gated graphene, and a pronounced low-frequency coupling with photons inherent to non-gated structures. It is also shown that the spatial dispersion of conductivity significantly augments the free path and cutoff frequency of SPPs, which is of great importance for practical applications.