Ground-state pairing correlations in the S4 symmetric microscopic model for iron-based superconductors

Abstract

We present the ground-state pairing correlations in the S4 symmetric microscopic model for iron-based superconductors, computed with the constrained-path Monte Carlo method. For various electron fillings and interaction strengths, we find that the sxy pairing dominates over other pairing correlations and is positive when the pair separation exceeds several lattice constants, both for iron-pnictides and iron-chalcogenides. These ground-state properties, especially the long-range part pairing correlations reconfirm the previous finite-temperature results published in Phys. Rev. Lett., 110 (2013) 107002. We further our study by including the nearest-neighbour interaction V and it is found that the sxy pairing correlation is slightly suppressed by increasing V.