Orbital-Fluctuation-Mediated Superconductivity in Iron Pnictides: Analysis of the Five-Orbital Hubbard-Holstein Model
Orbital-Fluctuation-Mediated Superconductivity in Iron Pnictides: Analysis of the Five-Orbital Hubbard-Holstein Model
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DOI：
10.1103/physrevlett.104.157001
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发表时间：
2010-04-16
影响因子：
8.6
通讯作者：
Onari, Seiichiro
中科院分区：
文献类型：
--
作者：
Kontani, Hiroshi;Onari, Seiichiro
在铁磷族化合物中，我们发现由于铁离子振荡引起的适度的电子-声子相互作用可以引起临界d轨道涨落，而不被库仑相互作用所禁止。这些波动引起了强烈的配对相互作用的s波超导（SC）状态没有符号反转（s（++）波状态），这是一致的实验观察到的超导性对杂质的鲁棒性。当库仑相互作用引起的磁涨落也很强时，随着杂质浓度的增加，SC态表现出从符号反转的s波态（s（+/-）-波态）到s（++）-波态的平滑过渡。
In iron pnictides, we find that the moderate electron-phonon interaction due to the Fe-ion oscillation can induce the critical d-orbital fluctuations, without being prohibited by the Coulomb interaction. These fluctuations give rise to the strong pairing interaction for the s-wave superconducting (SC) state without sign reversal (s(++)-wave state), which is consistent with experimentally observed robustness of superconductivity against impurities. When the magnetic fluctuations due to Coulomb interaction are also strong, the SC state shows a smooth crossover from the s-wave state with sign reversal (s(+/-)-wave state) to the s(++)-wave state as impurity concentration increases.