Evidence for Two Energy Gaps in Superconducting Ba0.6K0.4Fe2As2 Single Crystals and the Breakdown of the Uemura Plot

被引：107

作者：

Ren, Cong ^{[1
]}

Wang, Zhao-Sheng

Luo, Hui-Qian

Yang, Huan

Shan, Lei

Wen, Hai-Hu

机构：

[1] Chinese Acad Sci, Inst Phys, Natl Lab Superconduct, Beijing 100190, Peoples R China

来源：

PHYSICAL REVIEW LETTERS | 2008年 / 101卷 / 25期

关键词：

D O I：

10.1103/PhysRevLett.101.257006

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We report a detailed investigation on the lower critical field H-c1 of the superconducting Ba0.6K0.4Fe2As2 (122) single crystals. A pronounced kink is observed on the H-c1(T) curve, which is attributed to the existence of two superconducting gaps. By fitting the data H-c1(T) to the two-gap BCS model in the full temperature region, a small gap of Delta(a)(0)=2.0 +/- 0.3 meV and a large gap of Delta(b)(0)=8.9 +/- 0.4 meV are obtained. The in-plane penetration depth lambda(ab)(0) is estimated to be 105 nm corresponding to a rather large superfluid density, which points to the breakdown of the Uemura plot in 122 superconductors.

引用

页数：4

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