Geometry of the charge density wave in the kagome metal AV3Sb5
Geometry of the charge density wave in the kagome metal AV3Sb5
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Kagome 金属 AV3Sb5 中电荷密度波的几何形状
DOI：
10.1103/physrevb.104.195132
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发表时间：
2021-11-18
影响因子：
3.7
通讯作者：
Yan, Binghai
中科院分区：
文献类型：
--
作者：
Miao, H.;Li, H. X.;Yan, Binghai
Kagome晶格是拓扑和纠缠电子激发的肥沃平台。最近，在Z（2）kagome金属AV（3）Sb（5）（A = K，Cs，Rb）中观察到非常规电荷密度波（CDW）的实验证据。这一观察结果引发了人们对受抑晶体结构和费米表面不稳定性之间相互作用的广泛兴趣。在这里，我们分析了AV（3）Sb（5）中的晶格效应及其对CDW的影响。基于已发表的实验数据，我们表明，由于可果美层之间的相移，2x 2x 2 CDW打破了晶体的六重旋转对称性，并且可以解释扫描隧道光谱观察到的双重对称CDW峰强度。晶格和电子自由度之间的耦合产生了一个弱的一级结构转变，而没有连续的晶格动力学变化。我们的结果强调了晶格几何在正确理解AV（3）Sb（5）中的非常规电子序中的基本作用。
Kagome lattice is a fertile platform for topological and intertwined electronic excitations. Recently, experimental evidence of an unconventional charge density wave (CDW) is observed in a Z(2) kagome metal AV(3)Sb(5) (A = K, Cs, Rb). This observation triggers wide interest in the interplay between frustrated crystal structure and Fermi surface instabilities. Here, we analyze the lattice effect and its impact on CDW in AV(3)Sb(5). Based on published experimental data, we show that the 2x2x2 CDW breaks the sixfold rotational symmetry of the crystal due to the phase shift between kagome layers and can explain the twofold symmetric CDW peak intensity observed by scanning tunneling spectroscopy. The coupling between the lattice and electronic degrees of freedom yields a weak first-order structural transition without continuous change of lattice dynamics. Our result emphasizes the fundamental role of lattice geometry in proper understanding of unconventional electronic orders in AV(3)Sb(5).