2016/09/20 by Artur P. Durajski, Durajski, A. P., R. Szczȩśniak +1 · 1 citation
Physics and Astronomy · #Advanced Chemical Physics Studies #FOS: Physical sciences #Physics of Superconductivity and Magnetism #Superconductivity (cond-mat.supr-con) #Superconductivity in MgB2 and Alloys
paper · pdf · doi:10.48550/arxiv.1609.06079
openalex publication_date 2016/09/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
The high-temperature superconducting state in sulfur trihydride (TC=203~K) has been investigated in the context of the non-adiabatic and anharmonic effects. The Migdal-Eliashberg equations and the extended Eliashberg equations, which include the lowest-order vertex corrections, have been solved numerically in the self-consistent way. For R3m crystal structure, the lowest-order vertex corrections decrease the value of the Coulomb pseudopotential from 0.123 to 0.108. The anharmonic effects work antagonistically in relation to the vertex corrections shifting the value of μ⋆ to 0.156. The studies conducted for the structure Im3m, where the Eliashberg function includes both the non-adiabatic and anharmonic effects, prove the even higher value of μ⋆=0.185. Independently of the assumed method of the analysis, the nearly identical no mean-field dependence of the order parameter on the temperature was obtained: 2Δ(0)/kBTC∼ 4.7 - due to the significant strong-coupling and retardation effects: λ∼ 2 and kBTC\slash ω\rm ln∼ 0.15-0.19. It means that the classical equations of Migdal-Eliashberg can be treated as a correct effective model for the superconducting state in \rm H3S. This paper has shown that the McMillan or Allen-Dynes formulas substantially lower the value of the critical temperature in relation to the result obtained with the Eliashberg equations.