Scrutinizing the double superconducting gaps and strong coupling pairing in (Li1-xFex)OHFeSe

被引：78

作者：

Du, Zengyi ^{[1
,2
]}

Yang, Xiong ^{[1
,2
]}

Lin, Hai ^{[1
,2
]}

Fang, Delong ^{[1
,2
]}

Du, Guan ^{[1
,2
]}

Xing, Jie ^{[1
,2
]}

Yang, Huan ^{[1
,2
]}

Zhu, Xiyu ^{[1
,2
]}

Wen, Hai-Hu ^{[1
,2
]}

机构：

[1] Nanjing Univ, Ctr Superconducting Phys & Mat, Natl Lab Solid State Microstruct, Nanjing 210093, Jiangsu, Peoples R China

[2] Nanjing Univ, Dept Phys, Collaborat Innovat Ctr Adv Microstruct, Nanjing 210093, Jiangsu, Peoples R China

来源：

NATURE COMMUNICATIONS | 2016年 / 7卷

基金：

中国国家自然科学基金;

关键词：

EXCITATIONS; COEXISTENCE;

D O I：

10.1038/ncomms10565

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

In the field of iron-based superconductors, one of the frontier studies is about the pairing mechanism. The recently discovered (Li1 - xFex)OHFeSe superconductor with the transition temperature of about 40 K provides a good platform to check the origin of double super-conducting gaps and high transition temperature in the monolayer FeSe thin film. Here we report a scanning tunnelling spectroscopy study on the (Li1 - xFex)OHFeSe single crystals. The tunnelling spectrum mimics that of the monolayer FeSe thin film and shows double gaps at about 14.3 and 8.6 meV. Further analysis based on the quasiparticle interference allows us to rule out the d-wave gap, and for the first time assign the larger (smaller) gap to the outer (inner) Fermi pockets (after folding) associating with the d(xy) (d(xz)/d(yz)) orbitals, respectively. The gap ratio amounts to 8.7, which demonstrates the strong coupling mechanism in the present superconducting system.

引用

页数：8

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