Investigation of superconductivity in the single-walled carbon nanotubes

Superconductivity in the single-walled carbon nanotubes is investigated. First, effect of diameter increasing on the clean systems critical temperature, T_c, is calculated. Then effect of impurity doping on the reduction of critical temperature T_c, of single-walled carbon nanotubes, is discussed. Our calculations illustrate that metallic zigzag single-walled carbon nanotubes have higher T_c than armchair single-walled carbon nanotubes with approximately same diameters and T_c decreases by increasing diameter. This can explain why superconductivity could be found in the small diameter single-walled carbon nanotubes. We found for the impurity doped systems, impurity in the strong scattering regime can decrease T_c significantly while in the weak scattering regime T_c is not affected by impurity doping.