Phase diagram of the isovalent phosphorous-substituted 122-type iron pnictides

TL;DR

This paper models the phase diagram of phosphorous-doped BaFe2As2 using a two-orbital approach and BdG equations, successfully reproducing experimental phase transitions and superconductivity suppression.

Contribution

It introduces a minimal two-orbital model combined with BdG calculations to qualitatively reproduce the phase diagram of P-doped BaFe2As2.

Findings

Magnetic order is suppressed with P doping.

Superconductivity emerges and then disappears at high doping levels.

Model results align qualitatively with experimental data.

Abstract

Recent experiments demonstrated that isovalent doping system gives the similar phase diagram as the heterovalent doped cases. For example, with the phosphorous (P)-doping, the magnetic order in BaFe$_{2}$(As$_{1-x}$P$_{x}$)$_{2}$ compound is first suppressed, then the superconductivity dome emerges to an extended doping region but eventually it disappears at large $x$. With the help of a minimal two-orbital model for both BaFe$_{2}$As$_{2}$ and BaFe$_{2}$P$_{2}$, together with the self-consistent lattice Bogoliubov-de Gennes (BdG) equation, we calculate the phase diagram against the P content $x$ in which the doped isovalent P-atoms are treated as impurities. We show that our numerical results can qualitatively compare with the experimental measurements.