Superconductors with Mesoscopic Phase Separation

TL;DR

This paper proposes a model for high-temperature superconductivity that incorporates mesoscopic phase separation, particle interactions, and lattice softening, explaining experimental observations and predicting non-monotonic critical temperature behavior.

Contribution

It introduces a novel theoretical model that accounts for mesoscopic phase separation and repulsive interactions in superconductors, aligning with experimental data.

Findings

Phase separation requires significant repulsive forces.

Critical temperature can vary non-monotonically with phase fraction.

Superconductivity can exist in heterophase systems even if absent in pure samples.

Abstract

A model of superconductivity is proposed taking into account repulsive particle interaction, mesoscopic phase separation and softening of crystalline lattice. These features are typical of many high-temperature superconductors. The main results obtained for the model are: (i) phase separation is possible only if repulsive forces play a significant role; (ii) the critical temperature as a function of the superconducting phase fraction can have non-monotonic behaviour; (iii) superconductivity is possible in heterophase systems even when it would be forbidden in pure samples. These results are in agreement with experiments.