Explanation of the Phase Diagram of High-Temperature Superconductors in Terms of the Model of Negative-U Centers Superconductivity

K. D. Tsendin; B. P. Popov; D. V. Denisov

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Explanation of the Phase Diagram of High-Temperature Superconductors in Terms of the Model of Negative-U Centers Superconductivity

K. D. Tsendin·B. P. Popov·D. V. Denisov

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Abstract

It is demonstrated qualitatively how a unified explanation of the wide variety of different regions in a typical phase diagram of HTSC can be given in terms of the model of negative-U centers superconductivity. Both the existence of four regions (pseudogap, superconducting, non Fermi-liquid and Fermi-liquid), in the phase diagram and all the transitions between these regions were explained by assuming that negative-U centers exist in HTSC and qualitatively taking into account their thermodynamic and direct quantum-mechanical interaction with ordinary electrons from the valence band. It is found that the principal parameter determining the properties of HTSC in the model of negative-U centers is the relative concentration of electrons belonging to negative-U centers. The negative-U centers naturally determine both the superconducting properties of HTSC systems and the entire phase diagram in the normal state.

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K. D. Tsendin, B. P. Popov, D. V. Denisov. 2005-02-10. Explanation of the Phase Diagram of High-Temperature Superconductors in Terms of the Model of Negative-U Centers Superconductivity. https://arxiv.org/abs/cond-mat/0502261

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