Direct observation of dispersive Kondo resonance peaks in a heavy-fermion system
Direct observation of dispersive Kondo resonance peaks in a heavy-fermion system
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DOI：
10.1103/physrevlett.100.176402
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发表时间：
2008-05-02
影响因子：
8.6
通讯作者：
Yamagami, H.
中科院分区：
文献类型：
--
作者：
Im, H. J.;Ito, T.;Yamagami, H.
用Ce 4d-4f共振角分辨光电子能谱研究了准二维重费米子系统CeCoGe（1.2）Si（0.8）中强关联Ce 4f电子的电子结构.第一次，色散相干峰的f态跨越费米能级，所谓的近藤共振，直接观察到一起的杂化导带。此外，实验频带色散定量地与基于周期性安德森模型的简单的杂化带图片吻合得很好。所获得的物理量，即，相干温度，近藤温度，和质量增强，是可比的热力学测量的结果。这些结果表明Ce 4f电子在重费米子系统中的巡游性质，并阐明了它们的微观杂化机制.
Ce 4d-4f resonant angle-resolved photoemission spectroscopy was carried out to study the electronic structure of strongly correlated Ce 4f electrons in a quasi-two-dimensional nonmagnetic heavy-fermion system CeCoGe(1.2)Si(0.8). For the first time, dispersive coherent peaks of an f state crossing the Fermi level, the so-called Kondo resonance, are directly observed together with the hybridized conduction band. Moreover, the experimental band dispersion is quantitatively in good agreement with a simple hybridization-band picture based on the periodic Anderson model. The obtained physical quantities, i.e., coherent temperature, Kondo temperature, and mass enhancement, are comparable to the results of thermodynamic measurements. These results manifest an itinerant nature of Ce 4f electrons in heavy-fermion systems and clarify their microscopic hybridization mechanism.