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arXiv 1201.3002cond-mat.mtrl-scicond-mat.str-el
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晶格几何形状对铁磁绝缘体中磁振子霍尔效应的影响

Effect of lattice geometry on magnon Hall effect in ferromagnetic insulators

T. Ideue, Y. Onose, H. Katsura, Y. Shiomi, S. Ishiwata, N. Nagaosa, Y. Tokura

摘要:

本文研究了各种铁磁绝缘体磁振子的热霍尔效应。对于烧绿石铁磁绝缘体Lu $_2$ V $_2$ O $_7$、Ho $_2$ V $_2$ O $_7$和In $_2$ Mn $_2$ O $_7$,在居里温度$T_C$以下已经观察到有限的霍尔热导率。从温度和磁场的依赖性,得出结论,磁振子是负责的热霍尔效应。基于Dzyaloshinskiii-Moriya(DM)相互作用引起的动量空间Berry曲率的理论可以很好地解释磁振子的霍尔效应。该分析已扩展到具有钙钛矿结构的过渡金属(TM)氧化物。La $_2$、NiMnO $_6$和YTiO $_3$具有畸变的钙钛矿结构,晶胞中含有四个TM离子,热霍尔信号不存在或小得多。另一方面,在另一种铁磁钙钛矿氧化物BiMnO $_3$中,在$T_C$以下可辨别有限的热霍尔响应,其显示具有较大晶胞的轨道有序。烧绿石和钙钛矿绝缘体系中热霍尔效应的存在与否反映了DM诱导磁振子霍尔效应的几何和拓扑特征。

英文摘要:

We have investigated the thermal Hall effect of magnons for various ferromagnetic insulators. For pyrochlore ferromagnetic insulators Lu$_2$V$_2$O$_7$, Ho$_2$V$_2$O$_7$, and In$_2$Mn$_2$O$_7$, finite thermal Hall conductivities have been observed below the Curie temperature $T_C$ . From the temperature and magnetic field dependences, it is concluded that magnons are responsible for the thermal Hall effect. The Hall effect of magnons can be well explained by the theory based on the Berry curvature in momentum space induced by the Dzyaloshinskii-Moriya (DM) interaction. The analysis has been extended to the transition metal (TM) oxides with perovskite structure. The thermal Hall signal was absent or far smaller in La$_2$NiMnO$_6$ and YTiO$_3$, which have the distorted perovskite structure with four TM ions in the unit cell. On the other hand, a finite thermal Hall response is discernible below $T_C$ in another ferromagentic perovskite oxide BiMnO$_3$, which shows orbital ordering with a larger unit cell. The presence or absence of the thermal Hall effect in insulating pyrochlore and perovskite systems reflect the geometric and topological aspect of DM-induced magnon Hall effect.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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