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arXiv · 1007.1313

Effect of Impurities with Internal Structure on Multiband Superconductors - Possible Enhancement of Transition Temperature -

Mikito Koga·Masashige Matsumoto·Hiroaki Kusunose
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Abstract

We study inelastic (dynamical) impurity scattering effects in two-band superconductors with the same ($s_{++}$ wave) or different ($s_\pm$ wave) sign order parameters. We focus on the enhancement of the superconducting transition temperature $T_{\rm c}$ by magnetic interband scattering with the interchange of crystal-field singlet ground and multiplet excited states. Either the $s_{++}$-wave or $s_\pm$-wave state is favored by the impurity-mediated pairing, which depends on the magnetic and nonmagnetic scattering strengths derived from the hybridization of the impurity states with the conduction bands. The details are examined for the singlet-triplet configuration that is suggestive of Pr impurities in the skutterudite superconductor LaOs$_4$Sb$_{12}$.

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Mikito Koga, Masashige Matsumoto, Hiroaki Kusunose. 2010-07-08. Effect of Impurities with Internal Structure on Multiband Superconductors - Possible Enhancement of Transition Temperature -. https://doi.org/10.1143/jpsj.79.094704

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