Strong-coupling description of the high-temperature superconductivity in the molecular hydrogen

TL;DR

This paper investigates the thermodynamic properties of high-temperature superconductivity in molecular hydrogen at 428 GPa, revealing how the critical temperature and other parameters vary with Coulomb pseudopotential, highlighting deviations from BCS theory.

Contribution

It provides a detailed strong-coupling analysis of superconductivity in molecular hydrogen under high pressure, emphasizing the effects of Coulomb pseudopotential on key properties.

Findings

Critical temperature decreases from 179 K to 141 K with increasing Coulomb pseudopotential.

The ratio Δ(0)/k_B T_C varies from 4.71 to 3.60, differing from BCS predictions.

Electron effective mass is significantly enhanced and slightly increases with temperature, reaching 2.2 times the electron mass at T_C.

Abstract

The detailed study of the selected thermodynamic properties of the superconducting phase in the molecular hydrogen under the pressure at 428 GPa has been presented. For the increasing value of the Coulomb pseudopotential, $\mu^{*}\in<0.08,0.15>$, the following results have been obtained: (i) the critical temperature decreases from 179 K to 141 K, (ii) the ratio $R_{1}\equiv\Delta(0)/k_{B}T_{C}$ differs noticeably from the BCS value: $R_{1}\in<4.71,3.60>$; (iii) the electron effective mass is large and grows slightly together with the temperature ($[m^{*}_{e}/m_{e}]_{{\rm max}} = 2.2$ for $T = T_{C}$).