Strong-coupling superconductivity in CaLi₂ under the pressure of 100 GPa

Abstract

In presented paper the superconducting properties of compressed CaLi₂ compounds have been calculated for P2₁/c$P{2}_1/\mathrm{c}$ phase. Energy gap, critical temperature and electron effective mass are analyzed within the framework of the strong-coupling Eliashberg theory for a wide range of Coulomb pseudopotential μ^⋆∈〈0.1,0.3〉${\mu }^{\star }\in 〈0.1,0.3〉$. It has been stated that Δ(0)$\Delta \left(0\right)$ decreases from 6.01 meV to 3.62 meV, T  _C decreases from 29.31 K to 18.16 K and dimensionless ratio 2Δ(0)/k_BT_C$2\Delta \left(0\right)/k_B{T}_C$ decreases from 4.76 to 4.64 dependently on the assumed value of the Coulomb pseudopotential. Moreover, it has been proved, that the ratio of the electron effective mass to the electron band mass $m_e^{\star }/m_e$ is high in the whole range of the superconducting phase existence and reaches its maximum equal to 3.73 for the critical temperature regardless of the value of Coulomb pseudopotential.