Superconductivity from repulsive electronic correlations on alternant cuprate and iron-based lattices

摘要

A key question in the theory of high-temperature superconductivity is whether off-diagonal long-range order 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± condensate symmetries. ? 2013 Wiley Periodicals, Inc. High-temperature superconductivity can be induced by repulsive electronic correlations. Time-reversed electron pairs on cuprate and iron-based pnictide and chalcogenide alternant lattices can interact with a short-range Coulomb repulsion and a weaker longer range attractive tail. Such interacting electrons can collectively correlate to produce superconductivity. The alternant lattice structure is the key stabilizing feature of such a mechanism giving high-temperature superconductivity with dx2-y2 and s± condensate symmetries.