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arXiv · 1512.05799

Estimation of intraband and interband relative coupling constants from temperature dependences of the order parameter for two-gap superconductors

S. A. Kuzmichev·T. E. Kuzmicheva·S. N. Tchesnokov·V. M. Pudalov·A. N. Vasiliev
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Abstract

We present temperature dependences of the large and the small superconducting gaps measured directly by SnS-Andreev spectroscopy in various Fe-based superconductors and MgB$_2$. The experimental $Δ_{L,S}(T)$ are well-fitted with a two-gap model based on Moskalenko and Suhl system of equations (supplemented with a BCS-integral renormalization). From the the fitting procedure, we estimate the key attribute of superconducting state \textemdash relative electron-boson coupling constants and eigen BCS-ratios for both condensates. Our results evidence for a driving role of a strong intraband coupling in the bands with the large gap, whereas interband coupling is rather weak for all the superconductors under study.

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S. A. Kuzmichev, T. E. Kuzmicheva, S. N. Tchesnokov, V. M. Pudalov, A. N. Vasiliev. 2015-12-17. Estimation of intraband and interband relative coupling constants from temperature dependences of the order parameter for two-gap superconductors. https://doi.org/10.1007/s10948-016-3386-5

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