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Superconductivity, Charge Orderings and Phase Separations in Systems with Local Electron Pairing

S. Robaszkiewicz·G. Pawlowski
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Abstract

We study two effective models developed for description of superconductors with short-coherence length: (i) the extended Hubbard model with on-site attraction and intersite repulsion, (ii) the model of hard-core charged bosons on a lattice. The analysis is concentrated on the problem of phase separations and competition between superconductivity (SS) and charge-density-wave (CDW) orderings. The phase diagrams of the systems are shown to consist of at least seven different states, including 3 types of phase separated (PS) states: CDW-SS (PS1), CDW-normal (PS2) and the state of electron droplets (PS3). By taking into account the PS states and the effects of longer-range density-density interactions (beyond nearest neighbours) our work substantially generalizes and modifies the conclusions of previous works concerning the models considered.

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S. Robaszkiewicz, G. Pawlowski. 2007-02-27. Superconductivity, Charge Orderings and Phase Separations in Systems with Local Electron Pairing. https://arxiv.org/abs/cond-mat/0702638

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