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arXiv · 1711.05059

Coulomb repulsion of holes and competition between d_{x^2-y^2}-wave and s-wave parings in cuprate superconductors

V. V. Val'kov·D. M. Dzebisashvili·M. M. Korovushkin·A. F. Barabanov
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Abstract

The effect of the Coulomb repulsion of holes on the Cooper instability in an ensemble of spin-polaron quasiparticles has been analyzed, taking into account the peculiarities of the crystallographic structure of the CuO$_2$ plane, which are associated with the presence of two oxygen ions and one copper ion in the unit cell, as well as the strong spin-fermion coupling. The investigation of the possibility of implementation superconducting phases with d-wave and s-wave pairing of the order parameter symmetry has shown that in the entire doping region only the d-wave pairing satisfies the self-consistency equations, while there is no solution for the s-wave pairing. This result completely corresponds to the experimental data on cuprate HTSC. It has been demonstrated analytically that the intersite Coulomb interaction does not affect the superconducting d-wave pairing, because its Fourier transform $V_q$ does not appear in the kernel of the corresponding integral equation.

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V. V. Val'kov, D. M. Dzebisashvili, M. M. Korovushkin, A. F. Barabanov. 2017-11-14. Coulomb repulsion of holes and competition between d_{x^2-y^2}-wave and s-wave parings in cuprate superconductors. https://doi.org/10.1134/s1063776117110085

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