标题： NbSi$_{2}$中的声子Weyl点和非常规费米弧的手性边缘模式 显示英文标题

标题： Phonon Weyl points and chiral edge modes with unconventional Fermi arcs in NbSi$_{2}$

摘要： NbSi$_{2}$在 P6$_{2}$22 对称性下结晶，具有硅原子的螺旋链结构。 缺乏反演对称性，结合其螺旋结构，导致出现独特的物理性质。 反演对称性的破坏导致外尔点的出现，而螺旋结构则促进了螺旋边缘模式的形成。 因此，NbSi$_{2}$成为探索声子外尔点与螺旋声子边缘模式相互作用的理想平台。 例如，我们在$\bar{\text{K}}$点附近识别出一个由三个外尔点组成的结构，其陈数为$\mathcal{C} = +1$。 这些节点形成非常规的费米弧，连接着$\bar{\Gamma}$或$\bar{\text{K}}$点，这模拟了一个有效的陈数$\mathcal{C} = -2$。 显示英文摘要

摘要： NbSi$_{2}$ crystallizes in the P6$_{2}$22 symmetry, featuring chiral chains of Si atoms. The absence of inversion symmetry, combined with its chiral structure, gives arise to unique physical properties. The breaking of inversion symmetry leads to the emergence of Weyl points, while the chiral structure enables the formation of chiral edge modes. As a result, NbSi$_{2}$ serves as an ideal platform for exploring the interplay between phonon Weyl points and chiral phonon edge modes. For example, we identify the presence of a structure consisting of three Weyl points with a Chern number of $\mathcal{C} = +1$ around the $\bar{\text{K}}$ point. These nodes form unconventional Fermi arcs connecting the $\bar{\Gamma}$ or $\bar{\text{K}}$ points, which mimic an effective Chern number of $\mathcal{C} = -2$.