Berry Phase of Phonons and Thermal Hall Effect in Nonmagnetic Insulators.
Berry Phase of Phonons and Thermal Hall Effect in Nonmagnetic Insulators.
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DOI：
10.1103/physrevlett.123.255901
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发表时间：
2019-01
影响因子：
8.6
通讯作者：
Takuma Saito;Kou Misaki;H. Ishizuka;N. Nagaosa
中科院分区：
文献类型：
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作者：
Takuma Saito;Kou Misaki;H. Ishizuka;N. Nagaosa
从理论上研究了外加磁场作用下非磁性绝缘子中声子霍尔效应(PHE)的产生机制。Phe在(对)磁性化合物中是已知的，其中磁矩和自旋-轨道相互作用起着关键作用。与此形成鲜明对比的是，我们在这里讨论的是，在磁场作用下，非磁性带状绝缘体中也会发生PHE。我们发现，对Born-Oppenheimer近似的修正会引起磁场与声子之间的拉曼型相互作用，这种相互作用会引起声子带的Berry曲率。这种Berry曲率导致了非磁性带状绝缘体中有限的热霍尔电导率κ_{H}。计算了正方形晶格和蜂窝晶格的κ_{H}值。给出了室温下Si的κ_{H}的量级估计。
A mechanism for the phonon Hall effect (PHE) in nonmagnetic insulators under an external magnetic field is theoretically studied. PHE is known in (para)magnetic compounds, where the magnetic moments and spin-orbit interaction play an essential role. In sharp contrast, we here discuss that the PHE also occurs in nonmagnetic band insulators subject to the magnetic field. We find that a correction to the Born-Oppenheimer approximation gives rise to a Raman-type interaction between the magnetic field and the phonons; this interaction gives rise to the Berry curvature of a phonon band. This Berry curvature results in the finite thermal Hall conductivity κ_{H} in nonmagnetic band insulators. The value of κ_{H} is calculated for square and honeycomb lattices. The order of the magnitude estimation for κ_{H} is given for Si at room temperature.