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arXiv · 1004.5093

Single Impurity Problem in Iron-Pnictide Superconductors

Toshikaze Kariyado·Masao Ogata
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Abstract

Single impurity problem in iron-pnictide superconductors is investigated by solving Bogoliubov-de Gennes (BdG) equation in the five-orbital model, which enables us to distinguish s$_{+-}$ and s$_{++}$ superconducting states. We construct a five-orbital model suitable to BdG analysis. This model reproduces the results of random phase approximation in the uniform case. Using this model, we study the local density of states around a non-magnetic impurity and discuss the bound-state peak structure, which can be used for distinguishing s$_{+-}$ and s$_{++}$ states. A bound state with nearly zero-energy is found for the impurity potential $I\sim 1.0$ eV, while the bound state peaks stick to the gap edge in the unitary limit. Novel multiple peak structure originated from the multi-orbital nature of the iron pnictides is also found.

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Toshikaze Kariyado, Masao Ogata. 2010-04-28. Single Impurity Problem in Iron-Pnictide Superconductors. https://doi.org/10.1143/jpsj.79.083704

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