The thermodynamic critical field and specific heat of superconducting state in phosphorene under strain

In this work, we present the thermodynamic properties of the superconducting state in phosphorene. In particular, we have examined the electron doped [Formula: see text] and biaxially strained (4%) monolayer of black phosphorous, which exhibits best thermodynamic stability and highest superconducting critical temperature [Formula: see text] among all monolayer phosphorene structures. Due to the confirmed electron–phonon pairing mechanism and relatively high electron–phonon coupling constant in the studied material, we carried out the calculations in the framework of the Eliashberg formalism for a wide range of the Coulomb pseudopotential [Formula: see text]. We have determined the thermodynamic critical field [Formula: see text], and the specific heat difference [Formula: see text] between superconducting [Formula: see text] and normal state [Formula: see text] as the functions of the temperature. In addition, we have calculated the dimensionless parameters [Formula: see text]/[Formula: see text] and [Formula: see text]/[Formula: see text], and also found their significant deviation from the expectations of the BCS theory. In particular, [Formula: see text] and [Formula: see text] for [Formula: see text].

Estimation of the superconducting parameters for silane at high pressure

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〉.