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arXiv · 1106.5417

Nodal superconductivity in Ba(Fe$_{1-x}$Ru$_x$)$_2$As$_2$ induced by isovalent Ru substitution

X. Qiu·S. Y. Zhou·H. Zhang·B. Y. Pan·X. C. Hong·Y. F. Dai·Man Jin Eom·Jun Sung Kim·S. Y. Li
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Abstract

We present the ultra-low-temperature heat transport study of an iron-based superconductor Ba(Fe$_{0.64}$Ru$_{0.36}$)$_2$As$_2$ ($T_c$ = 20.2 K), in which the superconductivity is induced by isovalent Ru substitution. In zero field we find a large residual linear term $κ_0/T$, more than 40% of the normal-state value. At low field, the $κ_0/T$ shows an $H^{1/2}$ dependence. These provide strong evidences for nodes in the superconducting gap of Ba(Fe$_{0.64}$Ru$_{0.36}$)$_2$As$_2$, which mimics that in another isovalently substituted superconductor BaFe$_2$(As$_{1-x}$P$_x$)$_2$. Our results show that the isovalent Ru substitution can also induce nodal superconductivity in BaFe$_2$As$_2$, as P does, and they may have the same origin. We further compare them with other two nodal superconductors LaFePO and LiFeP.

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X. Qiu, S. Y. Zhou, H. Zhang, B. Y. Pan, X. C. Hong, Y. F. Dai, Man Jin Eom, Jun Sung Kim, S. Y. Li. 2011-07-10. Nodal superconductivity in Ba(Fe$_{1-x}$Ru$_x$)$_2$As$_2$ induced by isovalent Ru substitution. https://arxiv.org/abs/1106.5417

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