Angle resolved photoelectron spectroscopy study of hidden order and magnetic states in uranium compounds

铀基化合物的有序态（如磁性）一直是凝聚态物理研究的中心问题之一。特别是在Si_2Si_2中观察到的隐有序态，25年来一直受到人们的关注。在本研究中，我们进行了角分辨光电子能谱，这是一个强大的工具，了解材料的电子结构，了解这些有序状态的起源。我们发现，U 5f电子，这是负责这些有序状态，具有巡回字符。这是理解这些有序态的重要基础。

The ordered states such as magnetism in uranium based compounds have been one of the central issues in condensed matter physics. Especially, the hidden order state observed in Uru_2Si_2 has been attracting much attention for more than 25 years. In the present study, we have performed angle-resolved photoelectron spectroscopy, which is a powerful tool to understand electronic structure of materials, to understand the origin of those ordered states. We have found that U 5f electrons, which are responsible for those ordered states, have an itinerant character. This is very important basis for the understanding of these ordered states.