Scanning Tunneling Spectroscopy and Vortex Imaging in the Iron Pnictide Superconductor BaFe1.8Co0.2As2

被引：228

作者：

Yin, Yi ^{[1
]}

Zech, M. ^{[1
]}

Williams, T. L. ^{[1
]}

Wang, X. F. ^{[2
,3
]}

Wu, G. ^{[2
,3
]}

Chen, X. H. ^{[2
,3
]}

Hoffman, J. E. ^{[1
]}

机构：

[1] Harvard Univ, Dept Phys, Cambridge, MA 02138 USA

[2] Univ Sci & Technol China, Dept Phys, Hefei 230026, Anhui, Peoples R China

[3] Univ Sci & Technol China, Hefei Natl Lab Phys Sci Microscale, Hefei 230026, Anhui, Peoples R China

来源：

PHYSICAL REVIEW LETTERS | 2009年 / 102卷 / 09期

关键词：

D-WAVE SUPERCONDUCTOR; BI2SR2CACU2O8+DELTA; STATES; CORES;

D O I：

10.1103/PhysRevLett.102.097002

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We present an atomic resolution scanning tunneling spectroscopy study of superconducting BaFe1.8Co0.2As2 single crystals in magnetic fields up to 9 T. At zero field, a single gap with coherence peaks at Delta=6.25 meV is observed in the density of states. At 9 and 6 T, we image a disordered vortex lattice, consistent with isotropic, single flux quantum vortices. Vortex locations are uncorrelated with strong-scattering surface impurities, demonstrating bulk pinning. The vortex-induced subgap density of states fits an exponential decay from the vortex center, from which we extract a coherence length xi=27.6 +/- 2.9 A, corresponding to an upper critical field H-c2=43 T.

引用

页数：4

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