laboratoire pierre aigrain
électronique et photonique quantiques
laboratoire pierre aigrain

Séminaire exceptionnel 28 septembre 2010, 11h, Salle Conf IV

Tsuneya ANDO - Department of Physics, Tokyo Institute of Technology, Japan
Theory of excitons in carbon nanotubes

A carbon nanotube is composed of concentric tubes of rolled graphene sheets, on which hexagons are arranged in a helical fashion about the axis. Since the first discovery quite a number of studies have been reported on their electronic properties because of their unique topological structures. The purpose of this talk is to give a brief review on recent theoretical investigations on optical properties.

The topics include an effective-mass description of electronic states, interaction effects on the band structure, optical absorption for parallel polarization and strong exciton effect, the Aharonov-Bohm (AB) splitting observed recently, dark and bright excitons due to the short-range part of the Coulomb interaction causing mixing between K and K’ points, and their ordering and relative energy splitting and strong effects of AB flux, and two-phonon absorption due to exciton excited states, family behavior, effects of environmental dielectric material, exciton absorption for cross-polarized light, etc.