Iron based superconductors: Models and properties.

摘要

Discovered in 2008, the Iron based Superconductors (FeSCs) have added yet another avenue for researchers to explore and understand the riddle of High Temperature Superconductivity. With the highest obtained T c of ∼ 56 K in bulk and ∼ 65K in thin films, FeSCs stand only second to the Cuprate Superconductors which were discovered about twenty five years ago. So far, the process of uncovering the pairing mechanism and pairing symmetry remains the central quest of most theorists trying to understand a High Temperature Superconductor(HTSC). While a symmetry protected nodal d-- wave pairing has been firmly established for the Cuprates, no such consenses has been reached for the FeSCs, and a complete picture regarding the pairing mechanism is still lacking in either of the two.;In this work, we begin by briefly reporting the current experimental status in FeSCs, review some of the existing and newly proposed theoretical models for FeSCs which include LDA and effective tight binding models describing the kinematics and pairing symmetry, deduce properties and consequences of these models, and finally provide a comparison with experimental data which support or refute their key features.