From hidden to large-moment-antiferromagnetic order in URu2Si2: an x-ray study of 5f occupation and wave function symmetry.

在许多令人着迷的U金属间化合物中，u5f电子的能带形成和电子相关效应的复杂相互作用是一个尚未掌握的智力挑战。问题是，建模应该从能带理论开始还是从局部原子方法开始？这是特别麻烦的，因为到目前为止，无论是活性类原子态的存在，还是它们的对称性，在实验上都无法得到证实，而且对于5f壳层的填充也没有普遍接受的数字。利用最先进的同步加速器光谱学，我们已经证明多重态不仅存在于隐序化合物URu2Si2中；它们甚至存在于像UFe2Si2这样流动的泡利顺磁性化合物中，从而推翻了30年来认为能带结构可以起作用的观点。我们更愿意证明，由于残余局部方面，这些波段必须被强重整化。因此，后续项目不仅包括进一步的光谱研究（NIXS， HAXPES， ARPES），还应进行DFT(LDA)+DMFT计算，以定量描述U化合物的电子结构。

In many fascinating U intermetallic compounds, the intricate interplay of band formation and electron correlation effects of the U 5f electrons is an intellectual challenge that has not yet been mastered. The question is, should the modelling start with band theory or a local atomic approach? This has been particularly troublesome because neither the presence nor the symmetry of the active atomic-like states was so far experimentally accessible nor are there generally accepted numbers for the filling of the 5f shell. With state-of-the-art synchrotron spectroscopy, we have shown that multiplets persist not only in the hidden order compound URu2Si2; they even persist in an itinerant, Pauli paramagnetic compound like UFe2Si2 thus overturning the 30-year-old wisdom that band structure will do the job. We rather show, that these bands must be strongly renormalized due to the remnant local aspects. The follow-up project shall therefore not only include further spectroscopy investigations (NIXS, HAXPES, ARPES), in addition DFT(LDA)+DMFT calculations shall be performed for a quantitative description of the U compound’s electronic structure.