Effect of electron-phonon interactions on orbital fluctuations in iron-based superconductors
Effect of electron-phonon interactions on orbital fluctuations in iron-based superconductors
复制标题
电子-声子相互作用对铁基超导体轨道涨落的影响
DOI：
10.1103/physrevlett.112.027002
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
K. Nakamura and R. Arita
中科院分区：
文献类型：
--
作者：
Y. Nomura;K. Nakamura and R. Arita
为了研究电子-声子耦合是否能增强铁基超导体轨道波动的可能性，我们建立了一种包含声子相关项的有效低能模型。利用推导出的有效电子-声子相互作用和声子频率，我们估计了声子介导的有效场址轨道内或轨道间电子-电子吸引和交换或对跳项的静态部分为。我们用推导出的相互作用和随机相位近似下的库仑斥力来分析模型。我们发现电子-声子相互作用对轨道涨落的增强作用很小，而库仑斥力增强的自旋涨落占主导地位。它导致了间隙函数（波）中符号反转的超导态。
To investigate the possibility of whether electron-phonon coupling can enhance orbital fluctuations in iron-based superconductors, we develop anab initiomethod to construct the effective low-energy models including the phonon-related terms. With the derived effective electron-phonon interactions and phonon frequencies, we estimate the static part () of the phonon-mediated effective on site intra- or interorbital electron-electron attractions asand exchange or pair-hopping terms as. We analyze the model with the derived interactions together with the Coulomb repulsions within the random phase approximation. We find that the enhancement of the orbital fluctuations due to the electron-phonon interactions is small, and that the spin fluctuations enhanced by the Coulomb repulsions dominate. It leads to the superconducting state with the sign reversal in the gap functions (wave).