Institut for Solid State Physics, Vienna University of Technology, 1040 Vienna, Austria.
Phys Rev Lett. 2010 May 14;104(19):197002. doi: 10.1103/PhysRevLett.104.197002.
We study a four-band model for iron-based superconductors within the local density approximation combined with dynamical mean-field theory (LDA+DMFT). This successfully reproduces the results of models which take As p degrees of freedom explicitly into account and has several physical advantages over the standard five d-band model. Our findings reveal that the new superconductors are more strongly correlated than their single-particle properties suggest. Two-particle correlation functions unveil the dichotomy between local and ordered magnetic moments in these systems, calling for further experiments to better resolve the short time scale spin dynamics.
我们在局域密度近似（LDA）结合动态平均场理论（DMFT）的基础上，研究了一个四能带铁基超导体模型。该模型成功再现了那些明确考虑砷 p 自由度的模型的结果，并且相对于标准的五 d 带模型具有几个物理优势。我们的发现表明，这些新的超导体比其单粒子性质所暗示的更为强关联。双粒子相关函数揭示了这些体系中局域和有序磁矩之间的二分法，这需要进一步的实验来更好地解析短时间尺度的自旋动力学。
