Unbalanced superconductivity induced by the constant electron-phonon coupling on a square lattice

Abstract

In the present paper, we analyze the properties of the unbalanced superconducting state on a square lattice with the constant value of the electron-phonon coupling function. We conduct our analysis in the framework of the Eliashberg formalism, explicitly considering {\bf k}-dependence of the electron and phonon dispersion relations. It is found that the balanced superconducting state does not induce itself in the system due to the high value of the electron effective mass. However, in the unbalanced case the thermodynamic properties of the superconducting condensate can be distinctly different from the predictions of the Bardeen-Cooper-Schieffer theory; when the coupling constant value in the diagonal channel of the self-energy is diminished comparing to the non-diagonal channel. This is due to the reduced dimensionality of the tested system and the strong-coupling effects included in the Eliashberg formalism.

arXiv comment7 pages, 4 figures

References in corpus (9)

• Correlated Electrons in High Temperature Superconductors
• A Survey of the Van Hove Scenario for High-T_c Superconductivity With Special Emphasis on Pseudogaps and Striped Phases
• Specific heat of MgB${}_2$ in a one- and a two-band model from first-principles calculations
• The toy model for the high-Tc superconductivity
• Anisotropic superconductivity in the two-dimensional electron-phonon system
• Pressure effects on the unconventional superconductivity of the noncentrosymmetric LaNiC2
• Anisotropy of the gap parameter in the hole-doped cuprates
• Strong-coupling properties of unbalanced Eliashberg superconductors
• Pseudogap in Eliashberg approach based on electron-phonon and electron-electron-phonon interaction