Specific heat and thermodynamic critical field for the molecular metallic hydrogen

2012

PLoS ONE

The pairing mechanism for the high- superconductors based on the electron-phonon (EPH) and electron-electron-phonon (EEPH) interactions has been presented. On the fold mean-field level, it has been proven, that the obtained s-wave model supplements the predictions based on the BCS van Hove scenario. In particular: (i) For strong EEPH coupling and the energy gap () is very weak temperature dependent; up to the critical temperature extends into the anomalous normal state to the Nernst temperature. (ii) The model explains well the experimental dependence of the ratio on doping for the reported superconductors in the terms of the few fundamental parameters. In the presented paper, the properties of the d-wave superconducting state in the two-dimensional system have been also studied. The obtained results, like for s-wave, have shown the energy gap amplitude crossover from the BCS to non-BCS behavior, as the value of the EEPH potential increases. However, for the energy gap amplitude extends into the anomalous normal state to the pseudogap temperature. Finally, it has been presented that the anisotropic model explains the dependence of the ratio on doping for the considered superconductors.

Section: Resultsmentioning

confidence: 99%

Pairing Mechanism for the High-TC Superconductivity: Symmetries and Thermodynamic Properties

2012

PLoS ONE

“…23 It should be noted that until now, the properties of the superconducting state of metallic hydrogen have been described theoretically in the pressure range from p m to 3.5 TPa. [24][25][26][27][28][29] The obtained results suggest that the maximum value of the critical temperature is about 600 K for p 2 TPa. 30,31 Unfortunately, in the case of metallic hydrogen, the high value of the metallization pressure makes it impossible to carry out experiments that would confirm the theoretical predictions.…”

Section: Introductionmentioning

confidence: 87%

Estimation of the superconducting parameters for silane at high pressure

Durajski

2014

Mod. Phys. Lett. B

The properties of the superconducting state in the Cmca phase of silane ( SiH4 ) at the pressure of 250 GPa have been considered. In particular, the critical temperature (TC), the free energy difference between the superconducting and normal state (ΔF ≡ FS - FN), the thermodynamic critical field (HC) and the specific heat jump (ΔC ≡ CS - CN) have been determined. It has been shown that the dimensionless ratios: [Formula: see text] and RC ≡ ΔC(TC)/CN(TC) assume the values: RH(μ⋆) ∈ 〈0.147, 0.154〉 and RC(μ⋆) ∈ 〈2.20, 1.79〉, where the symbol μ⋆ denotes the Coulomb pseudopotential and μ⋆∈ 〈0.1, 0.3〉.

“…The Eliashberg equations have been solved using the iterative method, presented and tested in the papers .…”

Section: The Eliashberg Formalism On the Imaginary Axismentioning

confidence: 99%

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

Physica Status Solidi (b)

Szczęśniak

Huras

2013

The thermodynamic parameters of the superconducting state in PtH at the pressure 76GPa have been examined. The calculations have been carried out in the framework of the Eliashberg formalism. It has been found that the critical temperature (TC) changes in the range from 30.6 to 16.8K, depending on the assumed value of the Coulomb pseudopotential: . The other thermodynamic quantities differ significantly from the predictions of the classical BCS theory. In particular: (i) the parameter 2false(0false)/kBTC reaches the values from 4.25 to 3.98, where false(0false) denotes the low‐temperature order parameter. (ii) The ratio of the specific heat jump (C) to the specific heat in the normal state (CN) takes the values from 2.07 to 1.97. (iii) Finally, , where HC0 is the low‐temperature thermodynamic critical field.