Two types of s-wave pairing due to magnetic and orbital fluctuations in the two-dimensional 16-band d-p model for iron-based superconductors
Two types of s-wave pairing due to magnetic and orbital fluctuations in the two-dimensional 16-band d-p model for iron-based superconductors
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DOI：
10.1103/physrevb.81.054518
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发表时间：
2010-02-01
影响因子：
3.7
通讯作者：
Ono, Yoshiaki
中科院分区：
文献类型：
--
作者：
Yanagi, Yuki;Yamakawa, Youichi;Ono, Yoshiaki
我们使用随机相位近似研究了二维16波段d-p模型中的超导性，该模型是由与LaFeAsO带结构的紧密结合拟合提取的。当轨道内斥力U大于轨道间1 U′时，具有序参量符号反转的扩展s波（s(+/-)-波）配对由反铁磁自旋涨落介导，而当U < U′时，另一种不具有符号反转的s波（s(++)-波）配对由铁轨道涨落介导。由于电子-声子耦合，s(++)-波对得到增强，从而可以在实际参数区内以U b> U'展开。
We study superconductivity in the two-dimensional 16-band d-p model extracted from a tight-binding fit to the band structure of LaFeAsO, using the random phase approximation. When the intraorbital repulsion U is larger than the interorbital one U', an extended s-wave (s(+/-)-wave) pairing with sign reversal of order parameter is mediated by antiferromagnetic spin fluctuations, while when U < U' another kind of s-wave (s(++)-wave) pairing without sign reversal is mediated by ferro-orbital fluctuations. The s(++)-wave pairing is enhanced due to the electron-phonon coupling and then can be expanded over the realistic parameter region with U > U'.