Theoretical Study on Superconductivity of Q-Carbon Doped with Different Elements: <i>T</i>_c Reaching 59 K at Ambient Pressure

Studying superconductivity in different carbon structures is of great interest for revealing the mechanism of high-temperature superconductivity and for exploring possible room-temperature superconductors. Q-carbon offers a potential opportunity for studying these two aspects. Within the first-principles calculations, we analyze the effects of doping elements in the Q-carbon on the crystal structural stability, electronic structures, phonon spectra, and electron–phonon interactions. The results show that boron-doped Q-carbon possesses the highest superconducting transition temperature (Tc) of 59 K among all other element-doped systems. The superconductivity of Q-carbon mainly comes from the metalization transition and phonon softening; the latter is caused by the ion bond characteristics through the introduction of doping. This study provides a new perspective for exploring the relationship between carbon structure and superconductivity as well as a reference for exploring novel high-temperature superconductors.