Magnon thermal Hall effect in kagome antiferromagnets with Dzyaloshinskii-Moriya interactions
Magnon thermal Hall effect in kagome antiferromagnets with Dzyaloshinskii-Moriya interactions
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DOI：
10.1103/physrevb.98.094419
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发表时间：
2018-04
影响因子：
3.7
通讯作者：
P. Laurell;G. Fiete
中科院分区：
文献类型：
--
作者：
P. Laurell;G. Fiete
我们从理论上研究了反铁磁kagome自旋系统的磁性和拓扑性质的存在下，在平面内和平面外的Dzyaloshinskiii-Moriya相互作用。在铁黄钾铁矾等材料中，面内相互作用稳定了具有有限标量自旋手征的倾斜非共线“伞形”磁位形。我们推导出的倾斜角的表达式，并使用所得到的顺序作为一个自旋波分析的起点。我们发现拓扑磁振子带，其特征在于非零陈数。我们计算了磁振子热霍尔电导率，并提出铁黄钾铁矾作为一个有前途的候选系统，观察磁振子热霍尔效应在非共线自旋配置。我们还表明，可以通过改变施加的磁场，或在平面Dzyaloshinskiii-Moriya强度的热导率进行调谐。与以往的拓扑磁振子带的研究相比，发现即使在小的倾斜的限制，效果是大的。
We theoretically study magnetic and topological properties of antiferromagnetic kagome spin systems in the presence of both in- and out-of-plane Dzyaloshinskii-Moriya interactions. In materials such as the iron jarosites, the in-plane interactions stabilize a canted noncollinear "umbrella" magnetic configuration with finite scalar spin chirality. We derive expressions for the canting angle, and use the resulting order as a starting point for a spin-wave analysis. We find topological magnon bands, characterized by non-zero Chern numbers. We calculate the magnon thermal Hall conductivity, and propose the iron jarosites as a promising candidate system for observing the magnon thermal Hall effect in a noncollinear spin configuration. We also show that the thermal conductivity can be tuned by varying an applied magnetic field, or the in-plane Dzyaloshinskii-Moriya strength. In contrast with previous studies of topological magnon bands, the effect is found to be large even in the limit of small canting.