Electronic states and pairing symmetry in the two-dimensional 16 band d-p model for iron-based superconductor

TL;DR

This paper investigates the electronic states and pairing symmetry in a detailed 16-band d-p model for iron-based superconductors, using RPA to analyze potential superconducting states and their symmetries.

Contribution

It introduces a comprehensive 16-band model fitted to first-principles calculations and explores pairing symmetries within this framework using RPA.

Findings

Identification of possible s-wave and d-wave pairing states.

Analysis of pairing symmetry dependence on Coulomb interaction parameters.

Insights into the electronic structure relevant for superconductivity in FeAs planes.

Abstract

The electronic states of the FeAs plane in iron-based superconductors are investigated on the basis of the two-dimensional 16-band d-p model, where the tight-binding parameters are determined so as to fit the band structure obtained by the density functional calculation for LaFeAsO. The model includes the Coulomb interaction on a Fe site: the intra- and inter-orbital direct terms U and U', the exchange coupling J and the pair-transfer J'. Within the random phase approximation (RPA), we discuss the pairing symmetry of possible superconducting states including s-wave and d-wave pairing on the U'-J plane.