标题： 光学声子的本征热霍尔效应由离散旋转对称性增强 显示英文标题

标题： Intrinsic thermal Hall effect of optical phonons enhanced by discrete rotational symmetry

摘要： 我们研究了立方体系中由光学声子贡献的本征热霍尔电导率。 系统的离散旋转对称性在波矢空间的大多数区域分裂了横向模式的简并度，但在少数高对称线附近例外。 因此，在外加磁场存在的情况下，声子贝里曲率在这些高对称线上变得尖锐集中。 我们发现，贝里曲率的奇异分布诱导出了一种本征热霍尔电导率，与各向同性系统相比显著增强。 它在外加磁场 $B\ln B$ 和温度上表现出非线性的 $B$ 依赖关系和非单调的温度依赖性。 在高温下，它的符号反转并渐近地接近一个非零值。 我们的分析表明，这种行为源于不同高对称线上附近的贝里曲率贡献之间的竞争。 显示英文摘要

摘要： We investigate the intrinsic thermal Hall conductivity contributed by optical phonons in a cubic system. The discrete rotational symmetry of the system splits the degeneracy of transverse modes across most regions of wave-vector space, except along a few high-symmetry lines. Consequently, in the presence of an external magnetic field, phonon Berry curvatures become sharply peaked near these high-symmetry lines. We find that the singular distribution of the Berry curvature induces an intrinsic thermal Hall conductivity that is significantly enhanced compared to an isotropic system. It exhibits a nonlinear $B\ln B$ dependence on the magnetic field $B$ and a non-monotonic temperature dependence. At elevated temperatures, it reverses sign and approaches a non-vanishing value asymptotically. Our analysis indicates that the behavior results from competition between contributions from Berry curvatures near different high-symmetry lines.