The gap symmetry is marginal in high-Tc superconductivity: Isotropic s-wave pairing leads to either s or d-wave gap depending on the Coulomb pseudopotential

TL;DR

This paper explores how isotropic s-wave interactions in high-Tc superconductors can result in either s or d-wave pairing depending on the Coulomb pseudopotential, suggesting a possible transition between pairing symmetries with doping.

Contribution

It demonstrates that isotropic s-wave interactions can lead to different pairing symmetries in high-Tc superconductors based on Coulomb pseudopotential values, challenging traditional assumptions.

Findings

YBa2Cu3O7 may be d-wave superconductors

Bi2Sr2CaCu2O8 may be s-wave superconductors

Doping could induce s-to-d wave transition

Abstract

We point out that in two-dimensional systems like high-$T_c$ superconductors, an isotropic s-wave electron-phonon interaction in the momentum decoupling regime leads to either s or d-wave superconductivity depending on the conventional values of the Coulomb pseudopotential. It is therefore possible that $YBa_2Cu_3O_7$ is an anisotropic d-wave and $Bi_2Sr_2CaCu_2O_8$ an anisotropic s-wave superconductor both having the same pairing interaction and similar $T_c$'s. A transition from s-wave to d-wave superconductivity may also be possible by adjusting the doping.