Elementary excitations in cylindrical tubules

Exciton dynamics in carbon nanotubes: from the Luttinger liquid to harmonic oscillators

We show that the absorption spectrum in semiconducting nanotubes can be determined using the bosonization technique combined with mean-field theory and a harmonic approximation. In this framework, a multiple band semiconducting nanotube reduces to a system of weakly coupled harmonic oscillators. We also find that gaps of any size destroy the Luttinger liquid phase in single-walled carbon nanotubes and give rise to electron density fluctuations that resemble excitons built from quasiparticles. Interband processes, such as multiple exciton generation, become progressively weaker as the length to diameter ratio grows larger.

Strongly localized image states of spherical graphitic particles

We investigate the localization of charged particles by the image potential of spherical shells, such as fullerene buckyballs. These spherical image states exist within surface potentials formed by the competition between the attractive image potential and the repulsive centripetal force arising from the angular motion. The image potential has a power law rather than a logarithmic behavior. This leads to fundamental differences in the nature of the effective potential for the two geometries. Our calculations have shown that the captured charge is more strongly localized closest to the surface for fullerenes than for cylindrical nanotube.

Plasmon excitation in single-walled carbon nanotubes probed using charged particles: comparison of calculated and experimental spectra

We study ' the excitation of plasmons due to the incidence of a fast charged particle that passes through a single-wall carbon nanotube. We use a quantized hydrodynamic model, in which the σ and π electron systems are depicted as two interacting fluids moving on a cylindrical surface. Calculations of the average number of the excited plasmons and the corresponding energy loss probability for the swift electrons are compared with several experimental results for electron energy loss spectra recorded using transmission electron microscopes. We are able to identify the π and σ + π plasmon peaks and elucidate the origin of various spectral features observed in different experiments.

Thermal radiation from carbon nanotubes in the terahertz range

The thermal radiation from an isolated finite-length carbon nanotube (CNT) is theoretically investigated both in near- and far-field zones. The formation of the discrete spectrum in metallic CNTs in the terahertz range is demonstrated due to the reflection of strongly slowed-down surface-plasmon modes from CNT ends. The effect does not appear in semiconductor CNTs. The concept of a CNT as a thermal nanoantenna is proposed.