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Mesoscopic Phase Separation in Anisotropic Superconductors

V. I. Yukalov·E. P. Yukalova
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Abstract

General properties of anisotropic superconductors with mesoscopic phase separation are analysed. The main conclusions are as follows: Mesoscopic phase separation can be thermodynamically stable only in the presence of repulsive Coulomb interactions. Phase separation enables the appearance of superconductivity in a heterophase sample even if it were impossible in pure-phase matter. Phase separation is crucial for the occurrence of superconductivity in bad conductors. Critical temperature for a mixture of pairing symmetries is higher than the critical temperature related to any pure gap-wave symmetry of this mixture. In bad conductors, the critical temperature as a function of the superconductivity fraction has a bell shape. Phase separation makes the single-particle energy dispersion softer. For planar structures phase separation suppresses d-wave superconductivity and enhances s-wave superconductivity. These features are in agreement with experiments for cuprates.

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V. I. Yukalov, E. P. Yukalova. 2005-01-17. Mesoscopic Phase Separation in Anisotropic Superconductors. https://doi.org/10.1103/physrevb.70.224516

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