论文标题
Kagome超导体CSV3SB5中的极性依赖性电荷密度波
Polarity-dependent charge-density wave in a kagome superconductor CsV3Sb5
论文作者
论文摘要
极性表面和界面在实现材料的外来特性中起着关键作用，而对这种极性状态进行搜索对于扩大材料的功能至关重要。在这里，我们报告了CSV3SB5的微孔角度分辨光谱光谱，该光谱是最近发现的Kagome超导体AV3SB5（A = K，RB，CS）的成员，并显示了裂解表面的极性性质的证据，CS-和SB端接表现为具有不同的fermioligy的表面。 CS终止的表面显示，由于三维电荷密度波（CDW），在低温下，V衍生的带谱带的两倍增加了一倍，而SB端端的频带则没有显示出由于造性CDW而抑制了块状孔的抑制。必须纳入这种极地依赖性的带状结构，以了解AV3SB5表面上非常规超导和电荷顺序的起源。
Polar surface and interface play a pivotal role for realizing exotic properties of materials, and a search for such polar states is of crucial importance for expanding materials' functionality. Here we report micro-focused angle-resolved photoemission spectroscopy of CsV3Sb5, a member of recently discovered kagome superconductors AV3Sb5 (A = K, Rb, Cs), and show evidence for the polar nature of cleaved surface which is characterized by Cs- and Sb-terminated surfaces with markedly different fermiology. The Cs-terminated surface shows intriguing doubling of V-derived bands at low temperature associated with the band folding due to the three-dimensional charge-density wave (CDW), whereas the Sb-terminated one shows no band doubling or resultant CDW-gap opening indicative of the suppression of bulk-originated CDW due to polar charge. Such polar-surface-dependent band structure must be incorporated for understanding the origin of unconventional superconducting and charge order at the surface of AV3Sb5.
