标题： 多带电子系统中的声子模分裂和声子异常 显示英文标题

标题： Phonon mode splitting and phonon anomaly in multiband electron systems

摘要： 我们研究将手征费米子与局部、无色散的声子耦合所带来的拓扑后果。 这种相互作用导致声子谱分裂成三个能带：一个平带和两个具有线性色散的能带，所有这些能带在零波矢量处的一个节点点上简并。 平带表现出消失的贝里曲率，而线性色散的能带则携带非平凡的拓扑特征。 它们的贝里曲率场在动量空间中呈现出类似刺猬的结构，类似于单极子配置，并反映了底层费米系统的手征性。 此外，有效的声子响应揭示了声子宇称异常，可表现为声子电流中的不连续性。 这种异常来源于费米子格林函数的奇点，并表明拓扑信息从费米子传递到声子。 我们的结果表明，声子电流为电子手征性和拓扑结构提供了直接的探测手段。 该框架为将拓扑概念扩展到相互作用的玻色子系统提供了基础，并可能指导具有可调几何和拓扑性质的声子材料的设计。 显示英文摘要

摘要： We investigate the topological consequences of coupling chiral fermions to local, dispersionless phonons. This interaction induces a splitting of the phonon spectrum into three bands: a flat band and two bands with linear dispersion, all of which are degenerate at a nodal point located at zero wavevector. The flat band exhibits vanishing Berry curvature, while the linearly dispersing bands carry nontrivial topological features. Their Berry curvature fields assume a hedgehog-like structure in momentum space, analogous to monopole configurations, and reflect the chirality of the underlying fermionic system. Moreover, the effective phonon response reveals a phonon parity anomaly, observable as a discontinuity in the phonon current. This anomaly originates from the singularities of the fermion Green's function and signals the transfer of topological information from fermions to phonons. Our results demonstrate that phonon currents provide a direct probe of electronic chirality and topological structures. The framework offers a foundation for extending topological concepts to interacting bosonic systems and may guide the engineering of phononic materials with tunable geometric and topological properties.