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arXiv · 1410.0832

Unexpected impact of magnetic disorder on multiband superconductivity

M. M. Korshunov·D. V. Efremov·A. A. Golubov·O. V. Dolgov
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Abstract

We analyze how the magnetic disorder affects the properties of the two-band $s_\pm$ and $s_{++}$ models, which are subject of hot discussions regarding iron-based superconductors and other multiband systems like MgB$_2$. We show that there are several cases when the transition temperature $T_c$ is not fully suppressed by magnetic impurities in contrast to the Abrikosov-Gor'kov theory, but a saturation of $T_c$ takes place in the regime of strong disorder. These cases are: (1) the purely interband impurity scattering, (2) the unitary scattering limit. We show that in the former case the $s_\pm$ gap is preserved, while the $s_{++}$ state transforms into the $s_\pm$ state with increasing magnetic disorder. For the case (2), the gap structure remains intact.

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M. M. Korshunov, D. V. Efremov, A. A. Golubov, O. V. Dolgov. 2014-10-03. Unexpected impact of magnetic disorder on multiband superconductivity. https://doi.org/10.1103/physrevb.90.134517

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