Korshunov A, Hu H, Subires D, Jiang Y, Călugăru D, Feng X, Rajapitamahuni A, Yi C, Roychowdhury S, Vergniory M G, Strempfer J, Shekhar C, Vescovo E, Chernyshov D, Said A H, Bosak A, Felser C, Bernevig B Andrei, Blanco-Canosa S
European Synchrotron Radiation Facility (ESRF), BP 220, F-38043, Grenoble, France.
Donostia International Physics Center (DIPC), Paseo Manuel de Lardizábal, 20018, San Sebastián, Spain.
Nat Commun. 2023 Oct 20;14(1):6646. doi: 10.1038/s41467-023-42186-6.
Geometrically frustrated kagome lattices are raising as novel platforms to engineer correlated topological electron flat bands that are prominent to electronic instabilities. Here, we demonstrate a phonon softening at the k = π plane in ScVSn. The low energy longitudinal phonon collapses at ~98 K and q = [Formula: see text] due to the electron-phonon interaction, without the emergence of long-range charge order which sets in at a different propagation vector q = [Formula: see text]. Theoretical calculations corroborate the experimental finding to indicate that the leading instability is located at [Formula: see text] of a rather flat mode. We relate the phonon renormalization to the orbital-resolved susceptibility of the trigonal Sn atoms and explain the approximately flat phonon dispersion. Our data report the first example of the collapse of a kagome bosonic mode and promote the 166 compounds of kagomes as primary candidates to explore correlated flat phonon-topological flat electron physics.
几何阻挫的 Kagome 晶格正作为新型平台兴起，用于构建与电子不稳定性相关的拓扑电子平带。在此，我们展示了 ScVSn 在 k = π 平面处的声子软化现象。由于电子 - 声子相互作用，低能纵向声子在约 98 K 和 q = [公式：见原文] 处崩塌，且未出现长程电荷序，长程电荷序在不同的传播矢量 q = [公式：见原文] 处出现。理论计算证实了实验结果，表明主导不稳定性位于一个相当平坦模式的 [公式：见原文] 处。我们将声子重整化与三角 Sn 原子的轨道分辨磁化率相关联，并解释了近似平坦的声子色散。我们的数据报道了 Kagome 玻色子模式崩塌的首个实例，并推动将 166 种 Kagome 化合物作为探索相关平坦声子 - 拓扑平坦电子物理的主要候选材料。
