Li Kangkang
Department of Physics, Zhejiang Normal University, Jinhua 321004, People's Republic of China.
J Phys Condens Matter. 2022 Oct 28;34(50). doi: 10.1088/1361-648X/ac9bbb.
Materials with magnon Hall effect have potential applications in the field of spintronics and magnonics. The experimental observations of the magnon Hall effect in three-dimensional pyrochlore ferromagnets and two-dimensional kagome ferromagnets inspired the search for topological magnons in various lattice structures. The honeycomb-kagome (HK) lattice (also known as the edge-centered honeycomb lattice) can be seen as the combination of the honeycomb and kagome lattices. Hence, the Dzyaloshinskii-Moriya (DM) interaction is allowed and topological magnons are expected in the HK lattice, as the cases in the honeycomb and the kagome lattices alone. Here, we study the topological magnons in the HK lattice by calculating its band structure, Chern number, edge states and thermal Hall conductivity. It is shown that there are rich topological phases and phase transitions with the tuning of the model parameters. The finite thermal Hall conductivity induced by the DM interaction also has interesting behaviors, which are related to the topological phase transitions.
具有磁振子霍尔效应的材料在自旋电子学和磁子学领域具有潜在应用。在三维焦绿石铁磁体和二维 Kagome 铁磁体中对磁振子霍尔效应的实验观测激发了在各种晶格结构中寻找拓扑磁振子的研究。蜂窝 - Kagome（HK）晶格（也称为边心蜂窝晶格）可视为蜂窝晶格和 Kagome 晶格的组合。因此，与仅在蜂窝晶格和 Kagome 晶格中的情况一样，HK 晶格中允许存在 Dzyaloshinskii - Moriya（DM）相互作用并预期存在拓扑磁振子。在此，我们通过计算 HK 晶格的能带结构、陈数、边缘态和热霍尔电导率来研究其中的拓扑磁振子。结果表明，随着模型参数的调整，存在丰富的拓扑相和相变。由 DM 相互作用诱导的有限热霍尔电导率也具有有趣的行为，这与拓扑相变有关。
