First-principles investigation of the superconducting properties of thallium sulfide

Abstract

We conduct a theoretical, first-principles study of thallium sulfide with the space group FM-3M. We determine the electronic structure, phonon dispersion relations, Eliashberg spectral function, electron-phonon coupling constant (λ) and any superconductivity. The results indicate that this structure is characterized by a much larger electronic density of states at the Fermi level. Both the norm-conserving pseudopotential and ultra-soft pseudopotential are used to study its superconducting properties. The transition temperatures (Tc) for superconductivity are 9.3 K and 4.2 K, while the electron–phonon coupling constants are 0.79 and 0.59, respectively. Tc does not increase with increasing pressure. The superconductivity disappears when the pressure reaches 80 GPa.