Influence of the Coulomb Repulsions on the Formation of the Superconducting Gap of the Spin-Polaron Quasiparticles in Cuprates

Val'kov, V. V.; Korovushkin, M. M.; Barabanov, A. F. Source: JOURNAL OF LOW TEMPERATURE PHYSICS, 196 (1-2):242-252; 10.1007/s10909-018-02120-3 JUL 2019

Taking into account the real crystalline structure of the ${CuO}_{2}$ plane and the strong spin-fermion coupling, the influence of the on-site Coulomb repulsion of holes $U_{p}$ and the intersite Coulomb repulsion $V_{2}$ between holes located at the next-nearest-neighbor oxygen ions on the formation of the superconducting gap with the d-wave symmetry of the order parameter of the spin-polaron quasiparticles is studied. It is shown that the formation of the resulting superconducting gap within the spin-fermion model is caused by three components. The dependence of the narrowing of the superconducting gap on the values $U_{p}$ and $V_{2}$ is analyzed.