Observation of Fermi-surface-dependent nodeless superconducting gaps in Ba0.6K0.4Fe2As2

被引：870

作者：

Ding, H. ^{[1
,2
]}

Richard, P. ^{[3
]}

Nakayama, K. ^{[4
]}

Sugawara, K. ^{[4
]}

Arakane, T. ^{[4
]}

Sekiba, Y. ^{[4
]}

Takayama, A. ^{[4
]}

Souma, S. ^{[3
]}

Sato, T. ^{[4
]}

Takahashi, T. ^{[3
,4
]}

Wang, Z. ^{[5
]}

Dai, X. ^{[1
,2
]}

Fang, Z. ^{[1
,2
]}

Chen, G. F. ^{[1
,2
]}

Luo, J. L. ^{[1
,2
]}

Wang, N. L. ^{[1
,2
]}

机构：

[1] Chinese Acad Sci, Beijing Natl Lab Condensed Matter Phys, Beijing 100190, Peoples R China

[2] Chinese Acad Sci, Inst Phys, Beijing 100190, Peoples R China

[3] Tohoku Univ, Adv Inst Mat Res, WPI Res Ctr, Sendai, Miyagi 9808577, Japan

[4] Tohoku Univ, Dept Phys, Sendai, Miyagi 9808578, Japan

[5] Boston Coll, Dept Phys, Chestnut Hill, MA 02467 USA

来源：

EPL | 2008年 / 83卷 / 04期

基金：

美国国家科学基金会;

关键词：

D O I：

10.1209/0295-5075/83/47001

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We have performed a high-resolution angle- resolved photoelectron spectroscopy study on the newly discovered superconductor Ba(0.6)K(0.4)Fe(2)As(2) (T(c) = 37 K). We have observed two superconducting gaps with different values: a large gap (Delta similar to 12 meV) on the two small hole-like and electron-like Fermi surface (FS) sheets, and a small gap (similar to 6meV) on the large hole-like FS. Both gaps, closing simultaneously at the bulk transition temperature (T(c)), are nodeless and nearly isotropic around their respective FS sheets. The isotropic pairing interactions are strongly orbital dependent, as the ratio 2 Delta/k(B)T(c) switches from weak to strong coupling on different bands. The same and surprisingly large superconducting gap due to strong pairing on the two small FSs, which are connected by the (pi, 0) spin-density-wave vector in the parent compound, strongly suggests that the pairing mechanism originates from the inter-band interactions between these two nested FS sheets. Copyright (c) EPLA, 2008.

引用

页数：4

共 18 条

[1] Direct observation of particle-hole mixing in the superconducting state by angle-resolved photoemission [J].

Campuzano, JC ;

Ding, H ;

Norman, MR ;

Randeira, M ;

Bellman, AF ;

Mochiku, T ;

Kadowaki, K .

PHYSICAL REVIEW B, 1996, 53 (22) :14737-14740

[2] Superconductivity at 41 K and its competition with spin-density-wave instability in layered CeO1-xFxFeAs [J].

Chen, G. F. ;

Li, Z. ;

Wu, D. ;

Li, G. ;

Hu, W. Z. ;

Dong, J. ;

Zheng, P. ;

Luo, J. L. ;

Wang, N. L. .

PHYSICAL REVIEW LETTERS, 2008, 100 (24)

[3]

CHEN GF, 2008, CONDMATARXIV08062648, P35402

[4] A BCS-like gap in the superconductor SmFeAsO0.85F0.15 [J].

Chen, T. Y. ;

Tesanovic, Z. ;

Liu, R. H. ;

Chen, X. H. ;

Chien, C. L. .

NATURE, 2008, 453 (7199) :1224-1227

[5]

CHEN XH, 2008, CONDMATARXIV08033603, P35402

[6]

HASHIMOTO K, 2008, CONDMATARXIV08063149, P35402

[7]

HUANG Q, 2008, CONDMATARXIV08062776, P35402

[8] Iron-based layered superconductor La[O1-xFx]FeAs (x=0.05-0.12) with Tc=26 K [J].

Kamihara, Yoichi ;

Watanabe, Takumi ;

Hirano, Masahiro ;

Hosono, Hideo .

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2008, 130 (11) :3296-+

[9]

LIU C, 2008, CONDMATARXIV08062147, P35402

[10]

MA F, 2008, CONDMATARXIV08063526, P35402

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