Unexpected impact of magnetic disorder on multiband superconductivity

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.

5 pages, 4 figures

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Cited by in corpus (8)

• Unconventional disorder effects in correlated superconductors
• The fate of interaction-driven topological insulators under disorder
• Evolution of Superconducting Gaps in Th-Substituted Sm${}_{1-x}$Th${}_x$OFeAs Studied by Multiple Andreev Reflection Spectroscopy
• Pair breaking due to orbital magnetism in iron-based superconductors
• Topological nature of the transition between the gap and the gapless superconducting states
• Quasiparticle interference in multiband superconductors with strong coupling
• Impurity-induced smearing of the spin resonance peak in Fe-based superconductors
• Critical point of the transition between $s_{\pm }$ and $s_{++}$ states of a two-band superconductor with nonmagnetic impurities