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

¹ Department of Physics, Beijing Normal University - Beijing 100875, China
² Beijing Computational Science Research Center - Beijing 100084, China

^(a) txma@bnu.edu.cn

Received: 10 July 2013
Accepted: 19 October 2013

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 s_xy 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 s_xy pairing correlation is slightly suppressed by increasing V.