Tunneling spectroscopy of the superconducting gap in MgB2 -: art. no. 094504

被引：39

作者：

Ekino, T ^{[1
]}

Takasaki, T

Muranaka, T

Akimitsu, J

Fujii, H

机构：

[1] Hiroshima Univ, Fac Integrated Arts & Sci, Higashihiroshima 7398521, Japan

[2] Hiroshima Univ, Grad Sch Adv Sci Matter, Higashihiroshima 7398526, Japan

[3] Aoyama Gakuin Univ, Dept Phys, Setagaya Ku, Tokyo 1578572, Japan

来源：

PHYSICAL REVIEW B | 2003年 / 67卷 / 09期

关键词：

D O I：

10.1103/PhysRevB.67.094504

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The tunneling technique with a break junction has been applied to investigate the multiple superconducting gaps in MgB2. The observed gap features can be explained by combining inherent and induced order parameters. The largest gap of Delta = 9-10 meV corresponds to a very strong-coupling ratio 2Delta/k(B)T(c) = 5-6. Upon warming, this gap decreases in accordance with the BCS dependence, while the smaller gaps reduce faster than that but persist up to T-c. Therefore, the smallest gap of Delta = 2-2.5 meV gives 2Delta/k(B)T(c) = 1.2-1.5. The magnetic field can distinguish the behavior of the gap. The extrapolated highest gap-closing field for the largest gap agrees with the upper-critical field, thereby indicating that this gap is predominant to MgB2.

引用

页数：6

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