Magnetism and Superconductivity in the Two-Dimensional 16-Band d– p Model for Iron-Based Superconductors
Magnetism and Superconductivity in the Two-Dimensional 16-Band d– p Model for Iron-Based Superconductors
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DOI：
10.1143/jpsj.77.123701
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发表时间：
2008-09
影响因子：
1.7
通讯作者：
Y. Yanagi;Y. Yamakawa;Y. Ono
中科院分区：
文献类型：
--
作者：
Y. Yanagi;Y. Yamakawa;Y. Ono
基于二维16波段d - p模型，研究了铁基超导体中fe2 - As - 2平面的电子态，该模型包括铁位上的库仑相互作用、轨道内和轨道间直接项U和U ‘、洪德耦合J和对转移J ’。利用随机相位近似（RPA），我们得到了U ' - J平面上包含条纹和不相称序的磁相图。我们还求解了RPA内的超导间隙方程，发现对于大J，最有利的配对对称性是扩展s波，其序参量在空穴袋和电子袋之间改变其符号，而对于小J，最有利的配对对称性是d x y波。
The electronic states of the Fe 2 As 2 plane in iron-based superconductors are investigated on the basis of the two-dimensional 16-band d – p model which includes the Coulomb interaction on a Fe site: the intra- and inter-orbital direct terms U and U ', the Hund's coupling J and the pair-transfer J '. Using the random phase approximation (RPA), we obtain the magnetic phase diagram including the stripe and the incommensurate order on the U '– J plane. We also solve the superconducting gap equation within the RPA and find that, for large J , the most favorable pairing symmetry is extended s -wave whose order parameter changes its sign between the hole pockets and the electron pockets, while it is d x y -wave for small J .