Andreev reflection spectroscopy evidence for multiple gaps in MgB2 -: art. no. 064513

被引：24

作者：

Li, ZZ ^{[1
]}

Tao, HJ ^{[1
]}

Xuan, Y ^{[1
]}

Ren, ZA ^{[1
]}

Che, GC ^{[1
]}

Zhao, BR ^{[1
]}

机构：

[1] Chinese Acad Sci, Ctr Condensed Matter Phys, Beijing 100080, Peoples R China

来源：

PHYSICAL REVIEW B | 2002年 / 66卷 / 06期

关键词：

D O I：

10.1103/PhysRevB.66.064513

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

Andreev reflection tunneling spectroscopy on MgB2/PtIr point contacts have systematically been investigated. By fitting tunneling conductance to Blonder-Tinkham-Klapwijk theory, s-wave superconducting gaps were obtained. The distribution of the obtained gaps unequivocally shows two groups: one centered at 9.8 meV and the other peaked at 2.8 meV with a gap ratio of 3.5. For two typical gaps Delta(1)=1.92 meV and Delta(2)=3.45 meV their temperature-dependent behavior display that Delta(1)(T) unambiguously persists to the bulk T-c, 39 K, and Delta(2)(T) closes at 33 K. The results support multigap scenarios; in addition our experiments yield a much higher value of the large gap than the previous reports and theoretical predictions, indicating there may exist even stronger electron-phonon coupling in MgB2.

引用

页码：1 / 5

页数：5

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