Theoretical study of anisotropic tunnelling conductance in iron-based orbitally ordered superconductors

Abstract

We address here the role of Jahn-Tellar (JT) distortion on the superconducting (SC) gap in iron-based superconductors taking into account of the first and second nearest-neighbour (NN) electron hoppings in the square lattice within one band model approach. The Green's functions are calculated by using Zubarev's Green's function technique. The temperature dependent superconducting gap and the lattice strain are calculated from the correlation functions of the corresponding Green's functions and are computed self-consistently. The temperature dependent gap equations show that the superconducting gap is enhanced with the decrease of second nearest-neighbour hopping accompanied by the suppression of lattice strain near the superconducting transition temperature. The second nearest hopping introduces asymmetry in the tunnelling conductance.