Superconducting state above the boiling point of liquid nitrogen in the GaH3 compound

Abstract

The thermodynamic parameters of the superconducting state in the GaH3 compound under a pressure of 120 GPa have been determined. A wide range of Coulomb pseudopotential values has been taken into account: μ⋆∈〈0.1,0.2〉. It has been shown that, for the considered values of μ⋆, the superconducting state is characterized by a critical temperature which is higher than the boiling temperature of liquid nitrogen: TC∈(122.99,89.78) K. Other parameters significantly deviate from the predictions of BCS theory. In particular, the ratio of the energy gap to the critical temperature (RΔ ≡ 2Δ(0)/kBTC) changes in the range from 4.15 to 4.03. The ratio of the specific heat jump to the specific heat in the normal state (RC ≡ ΔC(TC)/CN(TC)) takes values from 1.87 to 1.58. The parameter , where HC is the thermodynamic critical field, is characterized in the following manner: RH∈〈0.147,0.150〉. Finally, it has been proven that the maximum value of the electron effective mass () equals 2.66me, where the symbol me denotes the electron band mass.