He Pan, Isobe Hiroki, Zhu Dapeng, Hsu Chuang-Han, Fu Liang, Yang Hyunsoo
Department of Electrical and Computer Engineering, National University of Singapore, Singapore, 117576, Singapore.
Institute for Nanoelectronic devices and Quantum computing, Fudan University, Shanghai, 200433, China.
Nat Commun. 2021 Jan 29;12(1):698. doi: 10.1038/s41467-021-20983-1.
The nonlinear Hall effect due to Berry curvature dipole (BCD) induces frequency doubling, which was recently observed in time-reversal-invariant materials. Here we report novel electric frequency doubling in the absence of BCD on a surface of the topological insulator BiSe under zero magnetic field. We observe that the frequency-doubling voltage transverse to the applied ac current shows a threefold rotational symmetry, whereas it forbids BCD. One of the mechanisms compatible with the symmetry is skew scattering, arising from the inherent chirality of the topological surface state. We introduce the Berry curvature triple, a high-order moment of the Berry curvature, to explain skew scattering under the threefold rotational symmetry. Our work paves the way to obtain a giant second-order nonlinear electric effect in high mobility quantum materials, as the skew scattering surpasses other mechanisms in the clean limit.
由贝里曲率偶极子（BCD）引起的非线性霍尔效应会导致倍频，这一现象最近在时间反演不变材料中被观测到。在此，我们报告了在零磁场下拓扑绝缘体BiSe表面不存在BCD时出现的新型电倍频现象。我们观察到，与施加的交流电流垂直的倍频电压呈现三重旋转对称性，而这排除了BCD的存在。与这种对称性相符的一种机制是斜散射，它源于拓扑表面态固有的手征性。我们引入了贝里曲率三重态，即贝里曲率的高阶矩，来解释三重旋转对称性下的斜散射。由于在清洁极限下斜散射优于其他机制，我们的工作为在高迁移率量子材料中获得巨大的二阶非线性电效应铺平了道路。
