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arXiv · 1604.01323

Effects of single- and multi-substituted Zn ions in doped-122 type iron-based superconductors

YuanYuan Zhao·Bo Li·Wei Li·Hong-Yi Chen·Kevin E. Bassler·C. S. Ting
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Abstract

Recent experiments on Zn-substituted 122-type iron-based superconductors (FeSCs) at electron- and hole- doped region provide us with a testing ground for understanding the effect of Zn impurities in these systems. Our first-principle calculations of the electronic structure reveal that the Zn 3d orbitals are far below the Fermi level and chemically inactive, while the Zn 4s-orbital is partially occupied and its wave function overlapping with those 3d-orbitals of neighboring Fe-ions. This suggests that the impurity effect is originating in the Zn 4s-orbital, not its 3d-orbitals. Employing a phenomenological two-orbital lattice model for 122-FeSCs and the self-consistent Bogoliubov-de Gennes equations, we study how the Zn-impurities suppress the superconductivity in electron- and hole- doped compounds. Our obtained results qualitatively agree with the experimental measurements.

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YuanYuan Zhao, Bo Li, Wei Li, Hong-Yi Chen, Kevin E. Bassler, C. S. Ting. 2016-04-05. Effects of single- and multi-substituted Zn ions in doped-122 type iron-based superconductors. https://doi.org/10.1103/physrevb.93.144510

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