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arXiv · 2210.08921

Rationalizing doping and electronic correlations in LaFe$_2$As$_2$

Tommaso Gorni·Diego Florez-Ablan·Luca de' Medici
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Abstract

We compute the electronic properties of the normal state of uncollapsed LaFe$_2$As$_2$, taking into account local dynamical correlations by means of slave-spin mean-field+density-functional theory. Assuming the same local interaction strength used to model the whole electron- and hole-doped BaFe$_2$As$_2$ family, our calculations reproduce the experimental Sommerfeld specific heat coefficient, which is twice the value predicted by uncorrelated band theory. We find that LaFe$_2$As$_2$ has a reduced bare bandwidth and this solves the apparent paradox of its sizeable correlations despite its nominal valence d$^{6.5}$, which would imply extreme overdoping and uncorrelated behaviour in BaFe$_2$As$_2$. Our results yield a consistent picture of the whole 122 family and point at the importance of the correlation strength, rather than sheer doping, in the interpretation of the phase diagram of iron-based superconductors

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Tommaso Gorni, Diego Florez-Ablan, Luca de' Medici. 2022-10-17. Rationalizing doping and electronic correlations in LaFe$_2$As$_2$. https://doi.org/10.1103/physrevb.107.125166

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