Superconducting order parameters in overdoped BaFe1.86Ni0.14As2 revealed by multiple Andreev reflection spectroscopy of planar break junctions

Article

关键词: IRON-BASED SUPERCONDUCTORS;    POINT-CONTACT;    RESONANCES;    TRANSPORT;   

DOI  :  10.1103/PhysRevB.104.174512

来源: SCIE

【 摘 要 】

Using multiple Andreev reflection spectroscopy, we studied superconductor-normal metal-superconductor semiballistic contacts with incoherent transport in overdoped pnictide superconductors BaFe1.86Ni0.14As2 with critical temperature Tc approximate to 12 K. We directly determined an anisotropic large gap with the characteristic ratios 2out L (0)/kBTc approximate to 6 and 2inL (0)/kBTc approximate to 4, almost isotropic small gap with 2S(0)/kBTc approximate to 2, and the temperature dependence of the resolved superconducting order parameters. Above the large gap position 2L, a fine dI(V )/dV structure fully vanishing at Tc and possibly caused by a resonant coupling with a bosonic mode was observed.

【 授权许可】

Free