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arXiv · 1108.4480

Unconventional multiband superconductivity with nodes in single-crystalline SrFe2(As_0.65P_0.35)2 as seen via 31P-NMR and specific heat

T. Dulguun·H. Mukuda·T. Kobayashi·F. Engetsu·H. Kinouchi·M. Yashima·Y. Kitaoka·S. Miyasaka·S. Tajima
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Abstract

We report 31P-NMR and specific heat measurements on an iron (Fe)-based superconductor SrFe2(As0.65P0.35)2 with Tc=26 K, which have revealed the development of antiferromagnetic correlations in the normal state and the unconventional superconductivity(SC) with nodal gap dominated by the gapless low-lying quasiparticle excitations. The results are consistently argued with an unconventional multiband SC state with the gap-size ratio of different bands being significantly large; the large full gaps in s\pm-wave state keep Tc high, whereas a small gap with a nodal-structure causes gapless feature under magnetic field. The present results will develop an insight into the strong material dependence of SC-gap structure in Fe-based superconductors.

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T. Dulguun, H. Mukuda, T. Kobayashi, F. Engetsu, H. Kinouchi, M. Yashima, Y. Kitaoka, S. Miyasaka, S. Tajima. 2011-08-23. Unconventional multiband superconductivity with nodes in single-crystalline SrFe2(As_0.65P_0.35)2 as seen via 31P-NMR and specific heat. https://doi.org/10.1103/physrevb.85.144515

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