Effect of Next-Nearest-Neighbor (NNN) Hopping and Exchange Interactions on High-Tc Superconductivity

Abstract

To investigate the effect of next-nearest-neighbor (NNN) hopping (t') and exchange interactions (J') on pairing mode (s- or d-wave) and hole-binding, the t-t'-J-J' model has been considered within an 8-site square cluster (tilted). Using the Lanczos exact diagonalization method, the dominance of s-wave is identified. The formation of two-hole pair is observed at J'/t > 0.5. However, appearance of superconducting condensation is absent in the model.