Description of the superconducting state in the high-pressure fcc phase of platinum-hydride

TL;DR

This paper investigates the thermodynamic properties of superconducting platinum hydride at high pressure using Eliashberg theory, revealing significant deviations from classical BCS predictions and how critical temperature varies with Coulomb pseudopotential.

Contribution

The study provides detailed thermodynamic analysis of PtH superconductivity at 76 GPa within the Eliashberg formalism, highlighting differences from BCS theory and the impact of Coulomb pseudopotential.

Findings

Critical temperature ranges from 30.6 K to 16.8 K.

Superconducting gap parameter from 4.25 to 3.98.

Specific heat jump ratio from 2.07 to 1.97.

Abstract

The thermodynamic parameters of the superconducting state in PtH at the pressure 76 GPa have been examined. The calculations have been carried out in the framework of the Eliashberg formalism. It has been found that the critical temperature changes in the range from 30.6 K to 16.8 K, depending on the assumed value of the Coulomb pseudopotential (0.1, 0.2 and 0.3). The other thermodynamic quantities differ significantly from the predictions of the classical BCS theory. In particular: (i) The parameter which corresponds to the superconducting band gap reaches the values from 4.25 to 3.98. (ii) The ratio of the specific heat jump to the specific heat in the normal state takes the values from 2.07 to 1.97. (iii) Finally, the parameter for the low-temperature thermodynamic critical field is in the range from 0.145 to 0.156.