Evolution of the Kondo lattice electronic structure above the transport coherence temperature
Evolution of the Kondo lattice electronic structure above the transport coherence temperature
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DOI：
10.1073/pnas.2001778117
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发表时间：
2020-09-22
影响因子：
11.1
通讯作者：
Shim, Ji Hoon
中科院分区：
文献类型：
--
作者：
Jang, Sooyoung;Denlinger, J. D.;Shim, Ji Hoon
近藤晶格的温度演化是一个长期的理论和实验研究课题，但它缺乏一个真正的微观描述的基本f-c杂化过程的关系的基本温度尺度的近藤屏蔽和费米液体晶格相干。在这里，f-c杂化带色散和费米能f光谱权重的近藤晶格系统CeCoIn 5的温度依赖性进行了研究，使用f-共振角分辨光电子能谱（ARPES）与足够的细节，允许直接比较第一原理动态平均场理论（DMFT）计算包含完整的现实主义的晶体电场状态。ARPES的结果，两个正交的（001）和（100）解理面和三个不同的f-c杂化配置，与DMFT提供的额外的微观洞察力，揭示了在费米面的参与温度远高于晶格相干温度，T* 近似为45 K，通常认为是这种行为的开始。DMFT结果显示了晶体电场（CEF）分裂在这种行为中的作用，并且特别强调了T* 以下的T依赖CEF简并交叉。最近的ARPES报告低T Luttinger定理失败CeCoIn 5被证明是不合理的，目前的ARPES数据，并没有发现在理论。
The temperature-dependent evolution of the Kondo lattice is a long-standing topic of theoretical and experimental investigation and yet it lacks a truly microscopic description of the relation of the basic f-c hybridization processes to the fundamental temperature scales of Kondo screening and Fermi-liquid lattice coherence. Here, the temperature dependence of f-c hybridized band dispersions and Fermi-energy f spectral weight in the Kondo lattice system CeCoIn5 is investigated using f-resonant angle-resolved photoemission spectroscopy (ARPES) with sufficient detail to allow direct comparison to first-principles dynamical mean-field theory (DMFT) calculations containing full realism of crystalline electric-field states. The ARPES results, for two orthogonal (001) and (100) cleaved surfaces and three different f-c hybridization configurations, with additional microscopic insight provided by DMFT, reveal f participation in the Fermi surface at temperatures much higher than the lattice coherence temperature, T* approximate to 45 K, commonly believed to be the onset for such behavior. The DMFT results show the role of crystalline electric-field (CEF) splittings in this behavior and a T-dependent CEF degeneracy crossover below T* is specifically highlighted. A recent ARPES report of low T Luttinger theorem failure for CeCoIn5 is shown to be unjustified by current ARPES data and is not found in the theory.