论文标题
观察由三维电荷密度波驱动的电子nematicity在Kagome晶格KV $ _3 $ SB $ _5 $中的观察
Observation of electronic nematicity driven by three-dimensional charge density wave in kagome lattice KV$_3$Sb$_5$
论文作者
论文摘要
Kagome超导体AV $ _3 $ SB $ _5 $（A = K，RB，CS）提供了一个肥沃的操场，用于研究有趣的现象，包括非平凡的乐队拓扑，超导性，巨大的综合大厅效果和电荷密度和电荷密度效应（CDW）。最近，$ C_2 $对称的对称阶段在AV $ _3 $ _3 $ sb $ _5 $中的超导状态之前，由于其对不寻常超导性的对称性的潜在遗传而引起了极大的关注。然而，直接证明了从倒数空间中CDW状态中电子结构旋转对称性破裂的直接证据仍然很少见，并且基本机制仍然模棱两可。该观察结果显示出非常规的单向性，表明旋转对称性从六倍到两倍。在2 $ \ times $ 2 $ \ times $ 2 $ 2 CDW相位的相邻平面之间的层间耦合导致首选的两倍对称电子结构。这些很少观察到的单向背折叠频带在kv $ _3 $ _3 $ _5 $中可能会为其特殊的收费订单和超导性提供重要的见解。
Kagome superconductors AV$_3$Sb$_5$ (A = K, Rb, Cs) provide a fertile playground for studying intriguing phenomena, including non-trivial band topology, superconductivity, giant anomalous Hall effect and charge density wave (CDW). Recently, a $C_2$ symmetric nematic phase prior to the superconducting state in AV$_3$Sb$_5$ drew enormous attention due to its potential inheritance of the symmetry of the unusual superconductivity. However, direct evidence on the rotation symmetry breaking of the electronic structure in the CDW state from the reciprocal space is still rare, and the underlying mechanism remains ambiguous. The observation shows unconventional unidirectionality, indicative of rotation symmetry breaking from six-fold to two-fold. The interlayer coupling between adjacent planes with $π$-phase offset in the 2$\times$2$\times$2 CDW phase leads to the preferred two-fold symmetric electronic structure. These rarely observed unidirectional back-folded bands in KV$_3$Sb$_5$ may provide important insights into its peculiar charge order and superconductivity.
