Two‐particle self‐consistent analysis for the electron‐hole asymmetry of superconductivity in cuprate superconductors

Abstract

In the hole‐doped type cuprate superconductors, it is well‐known that the superconducting transition temperature Tc exhibits a dome‐like structure against doping. On the other hand, recent experiments unveil that Tc in the electron‐doped compounds shows a monotonic increase with decreasing the doping, at least down to a very small doping rate. Our recent study for the three‐band d–p model has unveiled that this asymmetric behavior can be explained as a combined effect of the intrinsic electron‐hole asymmetry in systems comprising Cu3 d and O2 p orbitals and the band‐filling‐dependent vertex correction . In the present study, we study another compound Tl2 Ba2 CuO6 to show that this explanation can be applied to other cuprate superconductors with the small orbital mixture. By varying the d–p offset, we also study how the strength of the d–p hybridization controls the spin fluctuation and hence the pairing interaction.