Unconventional multiband superconductivity with nodes in single-crystalline SrFe2(As0.65P0.35)(2) as seen via P-31 NMR and specific heat

作者：Dulguun T^*; Mukuda H; Kobayashi T; Engetsu F; Kinouchi H; Yashima M; Kitaoka Y; Miyasaka S; Tajima S

来源：Physical Review B, 2012, 85(14): 144515.

DOI：10.1103/PhysRevB.85.144515

We report P-31-NMR and specific-heat measurements on an iron (Fe) based superconductor SrFe2(As0.65P0.35)(2) with T-c = 26 K, which have revealed the development of antiferromagnetic correlations in the normal state and unconventional superconductivity (SC) with the 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 the s(+/-)-wave state keep T-c high, whereas a small gap with a nodal structure causes a gapless feature under magnetic field. The present results will help develop insight into the strong material dependence of the SC gap structure in Fe-based superconductors.

• 出版日期2012-4-12