Fermiology of 122 family of Fe-based superconductors: An ab initio study

TL;DR

This study uses first-principles simulations to analyze how doping and substitution affect the Fermi surfaces of 122 Fe-based superconductors, revealing insights into their electronic structure and pairing mechanisms.

Contribution

It provides a detailed ab initio analysis of Fermi surface modifications due to doping in 122 superconductors, highlighting the role of FS dimensionality in pairing interactions.

Findings

Electron doping expands electron pockets and shrinks hole pockets.

Ru substitution up to 35% does not significantly alter Fermi surfaces.

P doping causes notable changes in hole Fermi surfaces.

Abstract

Fermiology of various 122 systems are studied through first principles simulation. Electron doping causes expansion of electron and shrinkage of hole Fermi pockets. Isovalent Ru substitution (upto 35%) makes no visible modification in the electron and hole like FSs providing no clue regarding the nature of charge carrier doping. However, in case of 32% P doping there are considerable changes in the hole Fermi surfaces (FSs). From our calculations, it is very clear that two dimensionality of FSs may favour electron pair scattering between quasi-nested FSs which has important bearings in various orders (magnetic, orbital, superconducting) present in Fe-based superconductors.