Effect of Coulomb repulsion on the London penetration depth in cuprate superconductors

Abstract

We study the effect of Coulomb repulsion between oxygen holes on the London penetration depth λ based on the concept of spin-polaron nature of Fermi quasiparticles in cuprates superconductors. It is shown that for the generally accepted values of the parameters of the spin-fermion model, taking into account the Coulomb interaction, both the one-site Hubbard Up and interaction between holes on the next-nearest-neighbor oxygen ions V2, allows one to achieve a much better agreement of the calculated temperature dependencies of the value λ−2 with the experimental data in La2−xSrxCuO4 in a wide range around optimal doping.