Stability of the Superconducting d-Wave Pairing Toward the Intersite Coulomb Repulsion in $$\hbox {CuO}_2$$ CuO 2 Plane

Abstract

Taking into account the real crystalline structure of the $$\hbox {CuO}_2$$ plane and the strong spin-fermion coupling, we study the influence of the intersite Coulomb repulsion between holes on the Cooper instability of the spin-polaron quasiparticles in cuprate superconductors. The analysis shows that only the superconducting d-wave pairing is implemented in the whole region of doping, whereas the solutions of the self-consistent equations for the s-wave pairing are absent. It is shown that intersite Coulomb interaction $$V_1$$ between the holes located at the nearest oxygen ions does not affect the d-wave pairing, because its Fourier transform $$V_q$$ vanishes in the kernel of the corresponding integral equation. The intersite Coulomb interaction $$V_2$$ of quasiparticles located at the next-nearest oxygen ions does not vanish in the integral equations, however, but it is also shown that the d-wave pairing is robust toward this interaction for physically reasonable values of $$V_2$$ .