Hydrogenation and doping induced one-dimensional high-temperature superconductivity in carbon nanotube

In recent years, the research on superconductivity in one-dimensional (1D) materials is attracting increasing attention due to its potential applications in low-dimensional nanodevices. However, the critical temperature (T_c) of 1D superconductors is low. In this work, we theoretically investigate the possible high-T_c superconductivity of (5,5) carbon nanotube (CNT). The pristine (5,5) CNT is a Dirac semimetal, and can be modulated to a semiconductor by fully hydrogenation. Interestingly, by further hole doping, it can be regulated into metallic state with the sp3-hybridized σ electrons metalized, and a giant Kohn anomaly appears in the optical phonons. The two factors together enhance the electron-phonon coupling, and lead to high-T_c superconductivity. When the hole doping concentration of hydrogenated-(5,5) CNT is 2.5 hole/cell, the calculated T_c is 82.3 K, exceeding the boiling point of liquid nitrogen. Therefore, the predicted hole-doped hydrogenated-(5,5) CNT provides a new platform for 1D high-T_c superconductivity and may have potential applications in 1D nanodevices.