Ab initio investigation of hydrogen-based high T csuperconductor that is stable under ambient environment

Abstract

We report an ab initio investigation of a hydrogen-based high-T c superconductor candidate - crystalized C4H4 in the cubic-gauche (cg-C4H4) structure, with the symmetry of space group I213. We find the cg-C4H4 structure to be stable under ambient environment; and the evaluation of the electron-phonon coupling strength indicates that the heavily doped cg-C4H4 can generate superconductivity with a T c ∼ 72 K. The high frequency vibrational modes of hydrogen atoms are found to play an important role in the total electron-phonon interaction strength, and the reduction of structural symmetry compared with graphene further enhances the electron-phonon coupling of the carbon framework. Our investigation illustrates a BCS route to realizing the hydrogen-based high T c superconductivity.