Spin fluctuations, interband coupling and unconventional pairing in iron-based superconductors

被引：139

作者：

Yao, Zi-Jian ^{[1
,2
,3
,4
]}

Li, Jian-Xin ^{[1
,2
,3
,4
]}

Wang, Z. D. ^{[1
,2
]}

机构：

[1] Univ Hong Kong, Dept Phys, Hong Kong, Hong Kong, Peoples R China

[2] Univ Hong Kong, Ctr Theoret & Computat Phys, Hong Kong, Hong Kong, Peoples R China

[3] Nanjing Univ, Natl Lab Solid State Microstruct, Nanjing 210093, Peoples R China

[4] Nanjing Univ, Dept Phys, Nanjing 210093, Peoples R China

来源：

NEW JOURNAL OF PHYSICS | 2009年 / 11卷

关键词：

LAYERED QUATERNARY COMPOUND; 43; K; LAO0.9F0.1-DELTA-FEAS; LAO1-XFXFEAS; INSTABILITY; SYSTEMS; ORDER;

D O I：

10.1088/1367-2630/11/2/025009

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

Based on an effective two-band model and using the fluctuation-exchange (FLEX) approach, we explore spin fluctuations and unconventional superconducting pairing in Fe-based layer superconductors. It is elaborated that one type of interband antiferromagnetic (AF) spin fluctuation stems from the interband Coulomb repulsion, whereas the other type of intraband AF spin fluctuation originates from the intraband Coulomb repulsion. Due to the Fermi-surface topology, a spin-singlet extended s-wave superconducting state is more favorable than the nodal d(XY)-wave state if the interband AF spin fluctuation is more significant than the intraband one, otherwise vice versa. It is also revealed that the effective interband coupling plays an important role in the intraband pairings, which is a distinct feature of the present two-band system.

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页数：8

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