Two pairing domes as Cu2+ varies to Cu3+

Abstract

Using a tight-binding two-orbital (dx2−y2, d3z2−r2) model and a random phase approximation treatment of the spin-fluctuation pairing vertex, we calculate the pairing strengths for a cuprate model in which the hole doping varies from Cu2+ to Cu3+. We find two domes of pairing strength: one corresponding to the traditional low hole doping regime and the other to the extremely overdoped regime discussed by Geballe and Marezio [Physica C 469, 680 (2009)]. In the overdoped regime we find that there is significant pairing strength in both the d-wave and s± channels.