Phase diagram of iron-pnictides if doping acts as a disorder

TL;DR

This paper explores the phase diagram of doped iron-pnictides assuming doping introduces non-magnetic impurities without changing carrier densities, revealing a coexistence phase and non-monotonic specific heat behavior consistent with experiments.

Contribution

It demonstrates that the phase diagram under impurity doping closely resembles the rigid band scenario, highlighting the coexistence of superconductivity and antiferromagnetism.

Findings

Coexistence of s+- superconductivity and antiferromagnetism in the phase diagram.

Non-monotonic jump in specific heat at the superconducting transition.

Quantitative agreement with experimental data on iron-pnictides.

Abstract

We obtain and analyze the phase diagram of doped iron-pnictides under the assumption that doping adds non-magnetic impurities to the system but does not change the densities of carriers. We show that the phase diagram is quite similar to the one obtained under the opposite rigid band assumption. In both cases, there is a phase where extended s+- superconductivity and antiferromagnetism co-exist. We evaluate the jump of the specific heat at the superconducting transition across the phase diagram and show that the jump is non-monotonic, with the maximum at the onset of the co-existence phase. Our results are in quantitative agreement with experiments on some iron-pnictides.