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Tail states in clean superconductors with magnetic impurities

A. V. Shytov·I. Vekhter·I. A. Gruzberg·A. V. Balatsky
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Abstract

We analyse the behavior of the density of states in a singlet s-wave superconductor with weak magnetic impurities in the clean limit. By using the method of optimal fluctuation and treating the order parameter self-consistently we show that the density of states is finite everywhere in the superconducting gap, and that it varies as $\ln N(E)\propto -|E-Δ_0|^{(7-d)/4}$ near the mean field gap edge $Δ_0$ in a d-dimensional superconductor. In contrast to most studied cases the optimal fluctuation is strongly anisotropic.

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A. V. Shytov, I. Vekhter, I. A. Gruzberg, A. V. Balatsky. 2003-12-16. Tail states in clean superconductors with magnetic impurities. https://doi.org/10.1103/physrevlett.90.147002

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