Superconductivity in homologous series of cuprates: Deep oscillations of the pairing coulomb potential

Superconducting pairing with a large momentum is characterized by a kinematic constraint, which effectively cuts off the screened Coulomb potential in the momentum transfer at scattering and leads to pairing potential oscillations in real space. Coulomb pairing in cuprates corresponds to a strong interaction between the paired particles lying both in the same cuprate plane and in two neighboring planes. This explains the experimental dependence of the transition temperature on the number of cuprate planes in a unit cell.