Superconducting pairing symmetry in iron pnictides

我们研究了铁化合物的超导态和正常态，以便了解整个相图。我们发现结构相变可以用电子-声子相互作用和库仑相互作用的顶点修正（高阶项）引起的轨道波动来解释。轨道波动有利于超导间隙函数，它没有任何变化。我们还发现跃迁现象的反常温度依赖性可以用轨道波动来解释。

We have studied both superconducting state and normal state of iron pnictides in order to understand the whole phase diagram. We have found that the structure phase transition can be explained by the orbital fluctuations, which are induced by the electron-phonon interaction and the vertex corrections (higher order terms) of the Coulomb interaction. The orbital fluctuations favor a superconducting gap function that has no sign change. We have also found that anomalous temperature dependence of transition phenomena is explained by the orbital fluctuations.