title: Quantum Monte Carlo study of a dominant s-wave pairing symmetry in iron-based superconductors.
abstract: We perform a systematic quantum Monte Carlo study of the pairing correlation in the S(4) symmetric microscopic model for iron-based superconductors. It is found that the pairing with an extensive s-wave symmetry robustly dominates over other pairings at low temperature in a reasonable parameter region regardless of the change of Fermi surface topologies. The pairing susceptibility, the effective pairing interaction, and the (π, 0) antiferromagnetic correlation strongly increase as the on-site Coulomb interaction increases, indicating the importance of the effect of electron-electron correlation. Our nonbiased numerical results provide a unified understanding of the superconducting mechanism in iron pnictides and iron chalcogenides and demonstrate that the superconductivity is driven by strong electron-electron correlation effects.
authors.affiliation: Department of Physics, Beijing Normal University, Beijing 100875, China.
authors.forename: Tianxing
authors.initials: T
authors.lastname: Ma
authors.forename: Hai-Qing
authors.initials: HQ
authors.lastname: Lin
authors.forename: Jiangping
authors.initials: J
authors.lastname: Hu