Terahertz Applications of Carbon Nanotubes and Graphene Nanoribbons

The results of the theoretical study of interband THz transitions in narrow-gap carbon nanotubes and graphene nanoribbons are reported. We consider dipole transitions across magnetically-induced gaps in armchair nanotubes, curvature-induced gaps in quasi-metallic nanotubes and edge-effect induced gaps in armchair nanoribbons. A giant enhancement of the transition matrix elements is discovered for all three types of nanostructures.