摘要
Considering the exciton effect, the excitation energy and its binding energy of the metallic single-walled carbon nanotubes （SWNTs） are theoretically studied by using＂ the simple tight-binding model, based on which the linear absorption spectra are also calculated. It is found that due to the trigonal warping effect, the excitation energies of the linear optical spectra all are split into two corresponding ones. Additionally, the splitting depends on both the chirality and the transition energy： （1） the splitting is maximal for the zigzag tubes, the splitting decreases with the increasing chiral angle; （2） the higher the transition energy is, the larger the splitting is. It is very interesting to find that the obtained results are in good agreement with the experimental results.
Considering the exciton effect, the excitation energy and its binding energy of the metallic single-walled carbon nanotubes （SWNTs） are theoretically studied by using＂ the simple tight-binding model, based on which the linear absorption spectra are also calculated. It is found that due to the trigonal warping effect, the excitation energies of the linear optical spectra all are split into two corresponding ones. Additionally, the splitting depends on both the chirality and the transition energy： （1） the splitting is maximal for the zigzag tubes, the splitting decreases with the increasing chiral angle; （2） the higher the transition energy is, the larger the splitting is. It is very interesting to find that the obtained results are in good agreement with the experimental results.
基金
Supported by the National Natural Science Foundation of China under Grant Nos 11304378 and 11304377, and the Fundamental Research Funds for the Central Universities under Grant No 2013QNA42.
