Superconductivity at 117 K in H-doped diamond

To explore the higher-temperature superconductivity at ambient pressure or near ambient pressure in diamond, we investigate the structure, electronic states, dynamics, and electron-phonon interactions of diamond doped by H atoms based on the first-principles calculations. The data on phonon spectra indicates that H-doped diamond is dynamically stable above 5 GPa. The hybridization between H and C induces the metallization transition. The analysis on electron-phonon interactions determines that H-doped diamond is superconducting above 5 GPa. The intercalatrion of H introduces more soft phonon modes, resulting in stronger superconductivity than other doped diamonds and hard materials. We predict that the superconducting transition temperature of H-doped diamond is 117.7 K at 5 GPa, which confirms that the superconductivity of diamond-like compounds can be further improved. Our study also shows that it is feasible for hard or superhard materials to obtain the high-temperature superconductivity at near ambient pressure.