The high-pressure superconductivity in SiH4: The strong-coupling approach

• Superconducting properties of SiH4 compound at 250 GPa.
• The Eliashberg approach.
• The high critical temperature.
• The non-BCS value of the ratio of the energy gap to the critical temperature.
• The large electron effective mass.

In the paper, the thermodynamic parameters of the high-pressure superconducting state in the SiH4 compound have been determined (p=250GPa). By using the Eliashberg equations in the mixed representation, the critical temperature, the energy gap, and the electron effective mass have been calculated. It has been stated that the critical temperature (TC) decreases from 51.65 K to 20.62 K, if the Coulomb pseudopotential increases (μ⋆∈〈0.1,0.3〉)(μ⋆∈〈0.1,0.3〉). The dimensionless ratio 2Δ(0)/kBTC2Δ(0)/kBTC decreases from 4.10 to 3.84, where the symbol Δ(0)Δ(0) denotes the value of the order parameter close to the zero temperature. The ratio of the electron effective mass to the band electron mass is high, and it reaches maximum equal to 1.95 for the critical temperature.