Excitons in narrow-gap carbon nanotubes

R. R. Hartmann, I. A. Shelykh, M. E. Portnoi
2011 Physical Review B  
We calculate the exciton binding energy in single-walled carbon nanotubes with narrow band gaps, accounting for the quasi-relativistic dispersion of electrons and holes. Exact analytical solutions of the quantum relativistic two-body problem are obtain for several limiting cases. We show that the binding energy scales with the band gap, and conclude on the basis of the data available for semiconductor nanotubes that there is no transition to an excitonic insulator in quasi-metallic nanotubes
more » ... tallic nanotubes and that their THz applications are feasible.
doi:10.1103/physrevb.84.035437 fatcat:ojjhpjz545gqxdygex3tnxm5ke