论文标题
用非弹性中子散射确定的拓扑声子条带的Chern数量
Chern numbers of topological phonon band crossing determined with inelastic neutron scattering
论文作者
论文摘要
谱带结构中的拓扑不变性（例如Chern数字）对于拓扑事项的分类至关重要，并决定了外来特性的发生，但是它们的直接光谱测定很大程度上受到电子带的限制。在这里，我们将非弹性中子散射与从头算计算结合使用，以确定MNSI和COSI单晶中的各种拓扑声子条带交叉。我们发现跨跨节点的Chern数与节点周围动量空间中的散射强度调制之间存在明显的关系。鉴于足够高的分辨率，我们的方法可用于确定拓扑声子带跨节点的任意较大的Chern数量。
Topological invariants in the band structure, such as Chern numbers, are crucial for the classification of topological matters and dictate the occurrence of exotic properties, yet their direct spectroscopic determination has been largely limited to electronic bands. Here, we use inelastic neutron scattering in conjunction with ab initio calculations to identify a variety of topological phonon band crossings in MnSi and CoSi single crystals. We find a distinct relation between the Chern numbers of a band-crossing node and the scattering intensity modulation in momentum space around the node. Given sufficiently high resolution, our method can be used to determine arbitrarily large Chern numbers of topological phonon band-crossing nodes.
