Band renormalization and Fermi surface reconstruction in iron-based superconductors
Band renormalization and Fermi surface reconstruction in iron-based superconductors
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DOI：
10.1103/physrevb.79.064517
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发表时间：
2009-01
影响因子：
3.7
通讯作者：
Shun-li Yu;Jing Kang;Jian-xin Li
中科院分区：
文献类型：
--
作者：
Shun-li Yu;Jing Kang;Jian-xin Li
利用涨落交换近似和三轨道模型，研究了铁基超导体的能带重整化、费米面重构和超导对对称性。我们发现，轨道间自旋涨落导致强各向异性带重正化，并且重正化是轨道相关的。结果表明，费米面的拓扑结构随着掺杂的不同而呈现出明显的变化，从电子型到空穴型，这与最近的实验结果是一致的。这表明库仑相互作用对能带重整化和电子费米口袋的拓扑结构有很大的影响。此外，由轨道间自旋涨落介导的对态具有扩展的$s$波对称性。
Using the fluctuation exchange approximation and a three-orbital model, we study the band renormalization, the Fermi surface reconstruction, and the superconducting pairing symmetry in iron-based superconductors. We find that the interorbital spin fluctuations lead to the strong anisotropic band renormalization and the renormalization is orbital dependent. As a result, the topology of Fermi surface displays distinct variation with doping from the electron type to the hole type, which is consistent with the recent experiments. This shows that the Coulomb interactions will have a strong effect on the band renormalization and the topology of the electron Fermi pocket. In addition, the pairing state mediated by the interorbital spin fluctuation is of an extended $s$-wave symmetry.