Ferromagnetic honeycomb systems are known to exhibit a magnonic topological phase under the existence of the next-nearest-neighbor Dzyaloshinskii-Moriya interaction (DMI). Motivated by the recent progress in the sublattice-specific control of magnetic anisotropy, we study the topological phase of magnon bands of a honeycomb ferromagnetic monolayer and a bilayer with sublattice symmetry breaking due to the different anisotropy energy in the presence of the DMI. We show that there is a topological phase transition between the topological magnon insulator and the topologically trivial magnon phase driven by the change of the relative size of the DMI and the anisotropy differences between the sublattices. The magnon thermal Hall conductivity is proposed as an experimental probe of the magnon topology.

中文翻译：

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亚晶格对称破缺驱动的蜂窝铁磁体磁子带拓扑相变

已知铁磁蜂窝系统在存在下一个最近邻 Dzyaloshinskii-Moriya 相互作用 (DMI) 的情况下表现出磁子拓扑相。受最近在磁各向异性的亚晶格特定控制方面取得进展的启发，我们研究了蜂窝铁磁单层和双层的磁子带的拓扑相，由于存在 DMI 的不同各向异性能量，亚晶格对称性破坏。我们表明，在拓扑磁振子绝缘体和拓扑微弱磁振子相之间存在拓扑相变，这是由 DMI 相对尺寸的变化和子晶格之间的各向异性差异驱动的。提出了磁振子热霍尔电导率作为磁振子拓扑的实验探针。