National Lab for Superconductivity, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.
Phys Rev Lett. 2010 Jul 9;105(2):027001. doi: 10.1103/PhysRevLett.105.027001. Epub 2010 Jul 6.
We report the first comprehensive high-resolution angle-resolved photoemission measurements on CeFeAsO, a parent compound of FeAs-based high temperature superconductors with a magnetic-structural transition at ∼150 K. In the magnetic-ordering state, four holelike Fermi surface sheets are observed near Γ(0,0), and the Fermi surface near M(±π,±π) shows a tiny electronlike pocket at M surrounded by four strong spots. The unusual Fermi surface topology deviates strongly from the band structure calculations. The electronic signature of the magnetic-structural transition shows up in the dramatic change of the quasiparticle scattering rate. A dispersion kink at ∼25 meV is observed for the first time in the parent compound of Fe-based superconductors.
我们报告了在 CeFeAsO 上进行的首次全面的高分辨率角分辨光电子能谱测量，CeFeAsO 是 FeAs 基高温超导体的母体化合物，在 ∼150 K 处存在磁结构转变。在磁有序态下，在 Γ(0,0)附近观察到四个空穴型费米面片，而在 M(±π,±π)附近的费米面显示出在 M 处被四个强点包围的微小电子型口袋。异常的费米面拓扑结构与能带结构计算强烈偏离。磁结构转变的电子特征表现在准粒子散射率的剧烈变化上。在 Fe 基超导体的母体化合物中，首次观察到在 ∼25 meV 处的色散拐点。
