Exciton dynamics in carbon nanotubes from many-body perturbation theory.

Understanding exciton decay processes in functional materials is of extreme interest due to the crucial role of time-resolved excited-state phenomena in energy conversion and storage and in photophysics applications. Nevertheless, theoretical predictions of the underlying interaction mechanisms involved are difficult to achieve. Many-body perturbation theory, within the GW approximation and the Bethe-Salpeter equation (GW-BSE), provides a reliable approach to examine structure-sensitive excitonic properties. In this work, we use recent GW-BSE development to account for excitonic bandstructures in the quasi 1D-systems of single-walled carbon nanotubes (SWCNTs). We study the relation between exciton dispersion and radiative lifetime, and explore excited-state propagation as a function of the tube structure and symmetry.