Abstract
Exciton effects in metallic carbon nanotubes with and without magnetic flux are studied in an effective-mass approximation. For parallel polarization, an exciton associated with the first excited bands has an appreciable binding energy even in the presence of strong screening of linear bands. The Aharonov-Bohm splitting of the exciton peak is slightly enhanced due to interaction effects. An Aharonov-Bohm gap in the linear bands is strongly enhanced, but the exciton binding energy tends to largely cancel this enhancement. For perpendicular polarization, there is essentially no exciton effect due to the absence of backscattering within linear bands and interband absorption is nearly suppressed by the depolarization effect.
5 More- Received 30 January 2008
DOI:https://doi.org/10.1103/PhysRevB.77.205407
©2008 American Physical Society