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arXiv · 2207.12142

Chern numbers of topological phonon band crossing determined with inelastic neutron scattering

Zhendong Jin·Biaoyan Hu·Yiran Liu·Yangmu Li·Tiantian Zhang·Kazuki Iida·Kazuya Kamazawa·A. I. Kolesnikov·M. B. Stone·Xiangyu Zhang·Haiyang Chen·Yandong Wang·I. A. Zaliznyak·J. M. Tranquada·Chen Fang·Yuan Li
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Abstract

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.

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Zhendong Jin, Biaoyan Hu, Yiran Liu, Yangmu Li, Tiantian Zhang, Kazuki Iida, Kazuya Kamazawa, A. I. Kolesnikov, M. B. Stone, Xiangyu Zhang, Haiyang Chen, Yandong Wang, I. A. Zaliznyak, J. M. Tranquada, Chen Fang, Yuan Li. 2022-07-25. Chern numbers of topological phonon band crossing determined with inelastic neutron scattering. https://doi.org/10.1103/physrevb.106.224304

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