High-resolution angle-resolved photoemission study of fine electronic states in electron-doped high-T_c superconductors

为了阐明高T_c铜氧化物超导性的起源，必须系统地研究各种超导体的电子态，并将它们与铜氧化物的电子态进行比较。最近发现的铁-磷属元素化物超导体是解决这个问题的最佳候选者。在这项研究中，我们进行了高分辨率的角度分辨光电子能谱的铁-磷属元素化物超导体和阐明基本的电子状态，如费米面和能带结构。此外，我们还直接观察到了超导能隙，建立了超导对对称性。我们还比较了铁磷族化合物和电子掺杂铜酸盐的实验电子态。

In order to elucidate the origin of superconductivity in high-T_c cuprates, it is indispensable to systematically investigate the electronic states of various superconductors and compare their electronic states with cuprates. Recently-discovered iron-pnictide superconductor is the best candidate to approach this issue. In this research, we have performed high-resolution angle-resolved photoemission spectroscopy of iron-pnictide superconductors and elucidated basic electronic states such as Fermi surface and band structure. In addition, we have directly observed the superconducting gap and established the superconducting pairing symmetry. We also compared the experimental electronic states between the iron pnictides and electron-doped cuprates.