Spin fluctuations and pairing symmetry in AxFe2−ySe2: dual effect of the itinerant and the localized nature of electrons
Spin fluctuations and pairing symmetry in AxFe2−ySe2: dual effect of the itinerant and the localized nature of electrons
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DOI：
10.1088/0953-8984/25/44/445702
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发表时间：
2013-05
期刊：
影响因子：
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通讯作者：
Shun-li Yu;Jiasen Guo;Jian-xin Li
中科院分区：
文献类型：
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作者：
Shun-li Yu;Jiasen Guo;Jian-xin Li
我们通过涨落交换近似研究了 AxFe2−ySe2 中的自旋涨落和配对对称性。除了现场相互作用之外，还包括次近邻反铁磁耦合 J2。我们发现电子的巡回性质和局域性质对于描述自旋涨落和配对对称性的最新实验结果都很重要。特别是，小的 J2 耦合可以将配对间隙从 d 波对称性更改为扩展的 s 波对称性。我们还研究了不同轨道的间隙函数的实空间结构，以便更深入地了解配对机制的本质。
We investigate the spin fluctuations and the pairing symmetry in AxFe2−ySe2 by the fluctuation exchange approximation. Besides the on-site interactions, the next-nearest-neighbor antiferromagnetic coupling J2 is also included. We find that both the itinerant and the localized natures of electrons are important to describe recent experimental results on the spin fluctuations and the pairing symmetry. In particular, a small J2 coupling can change the pairing gap from the d-wave symmetry to the extended s-wave symmetry. We have also studied the real-space structures of the gap functions for different orbits in order to gain more insight into the nature of the pairing mechanism.