Electron and Superconducting Properties of the AFeAs (A= Li, Na) Family Alkali-Metal Pnictides: Current Stage of the Research (mini-review)

TL;DR

This mini-review summarizes the current understanding of the physical, electronic, and superconducting properties of alkali-metal pnictides LiFeAs and NaFeAs, highlighting key models, experimental data, and unresolved issues.

Contribution

It provides a comprehensive overview of the current research stage on AFeAs superconductors, emphasizing theoretical models and experimental findings.

Findings

Multiple-gap superconductivity in AFeAs compounds

Identification of key unresolved problems in the field

Summary of experimental and theoretical research status

Abstract

The review is focused on one of the most exotic families of iron-based superconductors belonging to the AFeAs structural type, where A is alkali metal. We briefly concern physical and electron properties of the typical members of this family, LiFeAs and NaFeAs, discuss the theoretical models describing the multiple-gap superconducting state, and the experimental data available in literature. As well, we specify the main unsolved problems, that seem crucial for both the AFeAs family and for iron-based superconductors in general.