Superconductivity From Repulsive Electronic Correlations on Alternant Cuprate and Iron-based Lattices

Abstract

A key question in the theory of high-temperature superconductivity is whether Off-diagonal Long-Range Order (ODLRO) can be induced wholly or in large part by repulsive electronic correlations. Electron pairs on Cuprate and the iron-based pnictide and chalcogenide alternant lattices may interact with a strong short-range Coulomb repulsion and much weaker longer range attractive tail. Here we show that such interacting electrons can cooperate to produce a superconducting state in which time-reversed electron pairs effectively avoid the repulsive part but reside predominantly in the attractive region of the potential. The alternant lattice structure is a key feature of such a stabilization mechanism leading to the occurrence of high temperature superconductivity with dx2 -y2 or sign alternating s-wave or s plus/minus condensate symmetries.