Chirality dependence of exciton effects for e 33 and e 44 in single wall carbon nanotubes under axial magnetic field

摘要

Within the framework of tight-binding model, we have studied the excitons and binding energies of E33 and E44 transitions in the semiconducting single wall carbon nanotubes (SWNTs) under axial magnetic field (B). The obtained results show that the E33 and E44 excitons are split by the axial magnetic field, and the splitting depends on both diameter and chirality. In addition, it is more interesting to find that the binding energies of E33 and E44 transitions are also split by the axial magnetic field, whose splitting presents a clear family behavior, diameter and chirality dependence. However, due to the contrary family behavior of E33 and E44 transitions, a crossover of the splitting appears for some of the carbon nanotubes, which is similar to the overlap of E33 and E44 transition energies detected by the experiment.