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arXiv · 1007.0720

Impact of the Spin Density Wave Order on the Superconducting Gap of Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$

L. Chauvière·Y. Gallais·M. Cazayous·M. A. Méasson·A. Sacuto·D. Colson·A. Forget
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Abstract

We report a doping dependent electronic Raman scattering measurements on iron-pnictide superconductor Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$ single crystals. A strongly anisotropic gap is found at optimal doping for x=0.065 with $Δ_{max}\sim 5Δ_{min}$. Upon entering the coexistence region between superconducting (SC) and spin-density-wave (SDW) orders, the effective pairing energy scale is strongly reduced. Our results are interpreted in terms of a competition between SC and SDW orders for electronic state at the Fermi level. Our findings advocate for a strong connection between the SC and SDW gaps anisotropies which are both linked to interband interactions.

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L. Chauvière, Y. Gallais, M. Cazayous, M. A. Méasson, A. Sacuto, D. Colson, A. Forget. 2010-12-14. Impact of the Spin Density Wave Order on the Superconducting Gap of Ba(Fe$_{1-x}$Co$_x$)$_2$As$_2$. https://doi.org/10.1103/physrevb.82.180521

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