Terahertz and Sub-terahertz Responses of Finite Length Multiwall Carbon Nanotubes

The electromagnetic response of a multiwall carbon nanotube (MWNT) of small cross-sectional radius and finite length was theoretically studied in the terahertz and subterahertz regimes, by solving an integral equation. The polarizability of the MWNT peaks in the terahertz regime, depending on the length and the number of metallic shells. At lower frequencies, a strong depolarizing field creates a shielding effect: the penetration depth of the axial component of incident field depends on the frequency, the length, and the electron relaxation time. The screening effect makes MWNTs promising as interconnects.