Tight-binding Model Study Of The Effect Of Lattice Distortion On Superconducting Gap In Iron-based Superconductors: One Band Approach.

摘要

We propose a tight-binding one-band model for the iron-based superconductors. The Hamiltonian incorporates Jahn-tellar (JT) distortion in the degenerate dxz and d_Yz orbitals and superconductivity in both the orbitals with s± pairing symmetry. The electron Green's functions are calculated by using Zubarev's Green's function technique from which the temperature dependent gap equations for superconductivity and JT distortion are calculated from the corresponding electron Green's functions. The gap equations are computed numerically and self-consistently taking 100 ×100 grid points for the electron momentum. Interplay of orbital ordering and superconductivity is investigated by varying different model parameters of the system.