Plasmons in Cylindrical 2D Materials as a Platform for Nanophotonic Circuits

Materials of reduced dimensionality (graphene, thin BN layers, etc.) open new pathways to control electromagnetic fields at the nanoscale by the excitation, of tunable and highly confined propagating surface plasmon-polaritons. However, compressing and channeling of plasmons along 2D ribbons suffer from scattering at edges. The concept of using edgeless 2D rolled-up sheets, in particular carbon nanotubes (CNTs), for potential integration into plasmonic nanocircuits has not been explored yet. Apart from supporting plasmons with extremely short wavelengths (providing thus a strong light compression), the optical properties of CNTs are highly sensitive to the environment and external fields. Here, we study the launching and propagation of CNT plasmons in different key plasmonic structures, which include both coupled CNT waveguides and coupled CNT graphene resonators. We also show an efficient way of launching and phase control of propagating graphene plasmons with the help of a CNT antenna. Combining CNTs with graphene could become a promising route toward ultracompact plasmon circuitry at the nanoscale.