Itinerant to localized transition of f electrons in the antiferromagnetic superconductor UPd 2 Al 3
Itinerant to localized transition of f electrons in the antiferromagnetic superconductor UPd 2 Al 3
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DOI：
10.1038/nphys651
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发表时间：
2007-05
期刊：
影响因子：
19.6
通讯作者：
S. Fujimori;Y. Saitoh;T. Okane;A. Fujimori;H. Yamagami;Y. Haga;E. Yamamoto;Y. Ōnuki
中科院分区：
文献类型：
--
作者：
S. Fujimori;Y. Saitoh;T. Okane;A. Fujimori;H. Yamagami;Y. Haga;E. Yamamoto;Y. Ōnuki
在重费米子化合物中，随着温度的变化，f电子表现出流动和局部的行为。在特征温度T*以上，它们的磁性可以用完全“局域化”的f电子模型来描述。另一方面，在t *以下，它们的费米表面可以用“流动”的f-电子模型来解释。这两种模型假设电子的性质完全不同，它们如何在这些状态之间转换作为温度的函数，在它们的电子结构水平上从未被理解过。在这里，我们使用角分辨光电子能谱研究了重费米子反铁磁超导体upd2al3在vet *以下和上面的能带结构，发现在低温下形成费米表面的能带在高温下被排除在费米表面之外。这一结果表明，相同的电子既可以是流动的，也可以是局部的。
In heavy-fermion compounds,felectrons show both itinerant and localized behaviour depending on the temperature. Above a characteristic temperature,T*, their magnetic properties can be described by completely ‘localized’f-electron models. On the other hand, well belowT*, their Fermi surfaces can be explained by the ‘itinerant’f-electron model. These two models assume totally different natures of thefelectrons, and how they transform between these states as a function of temperature has never been understood at the level of their electronic structures. Here, we use angle-resolved photoelectron spectroscopy to study the band structure of the heavy-fermion antiferromagnetic superconductor UPd2Al3below and aboveT*, and find that thefbands, which form the Fermi surfaces at low temperatures, are excluded from the Fermi surfaces at high temperatures. This result demonstrates how the samefelectrons can be both itinerant and localized.