Protracted Kondo screening and kagome bands in the heavy-fermion metal Ce3Al
Protracted Kondo screening and kagome bands in the heavy-fermion metal Ce3Al
复制标题
重费米子金属 $mathrmCe_3mathrmAl$ 中的延长近藤屏蔽和戈薇带
DOI：
10.1103/physrevb.102.155140
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发表时间：
2020
影响因子：
3.7
通讯作者：
Haiyan Lu
中科院分区：
文献类型：
--
作者：
Li Huang;Haiyan Lu
Ce3Al 是一种典型的重费米子化合物，具有多个晶相。在这里，我们尝试结合密度泛函理论和单点动态平均场理论来研究其在六方相（α-Ce3Al）和立方相（β-Ce3Al）中的电子结构。我们证实，两个相中的 4f 价电子都是流动的，并伴有强烈的价态波动。它们的 4f 能带结构通过电子相关性被严重重整化，从而产生很大的有效电子质量。两个阶段的近藤筛选都会在很宽的温度范围内延长，因为单杂质近藤温度 TK 远高于相干近藤温度 TK*。特别是，α-Ce3Al的晶体结构形成层状kagome晶格。我们在其准粒子能带结构中观察到明显的戈薇衍生的平带和狄拉克锥体（或间隙）。因此，表明六方相 Ce3Al 是重费米子 kagome 金属的有前途的候选者。
Ce3Al is an archetypal heavy-fermion compound with multiple crystalline phases. Here, we try to investigate its electronic structures in the hexagonal phase (α-Ce3Al) and cubic phase (β-Ce3Al) by means of a combination of density functional theory and single-site dynamical mean-field theory. We confirm that the 4f valence electrons in both phases are itinerant, accompanied by strong valence state fluctuations. Their 4f band structures are heavily renormalized by electronic correlations, resulting in large effective electron masses. The Kondo screening in both phases would be protracted over a wide range of temperature since the single-impurity Kondo temperature TK is much higher than the coherent Kondo temperature TK∗. Especially, the crystal structure of α-Ce3Al forms a layered kagome lattice. We observe conspicuous kagome-derived flat bands and Dirac cones (or gaps) in its quasiparticle band structure. Therefore, it is suggested that the hexagonal phase of Ce3Al is a promising candidate for a heavy-fermion kagome metal.