Department of Physics, Pennsylvania State University, University Park, PA, USA.
Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA, USA.
Nat Commun. 2023 Jan 23;14(1):364. doi: 10.1038/s41467-023-35989-0.
Nonlinear Hall effect (NLHE) is a new type of Hall effect with wide application prospects. Practical device applications require strong NLHE at room temperature (RT). However, previously reported NLHEs are all low-temperature phenomena except for the surface NLHE of TaIrTe. Bulk RT NLHE is highly desired due to its ability to generate large photocurrent. Here, we show the spin-valley locked Dirac state in BaMnSb can generate a strong bulk NLHE at RT. In the microscale devices, we observe the typical signature of an intrinsic NLHE, i.e. the transverse Hall voltage quadratically scales with the longitudinal current as the current is applied to the Berry curvature dipole direction. Furthermore, we also demonstrate our nonlinear Hall device's functionality in wireless microwave detection and frequency doubling. These findings broaden the coupled spin and valley physics from 2D systems into a 3D system and lay a foundation for exploring bulk NLHE's applications.
非线性 Hall 效应（NLHE）是一种具有广泛应用前景的新型 Hall 效应。实际的器件应用需要在室温（RT）下具有强的 NLHE。然而，除了 TaIrTe 的表面 NLHE 之外，以前报道的 NLHE 都是低温现象。由于其能够产生大的光电流，因此强烈需要体 RT NLHE。在这里，我们展示 BaMnSb 中的自旋-谷锁定狄拉克态可以在 RT 下产生强的体 NLHE。在微尺度器件中，我们观察到了内在 NLHE 的典型特征，即横向 Hall 电压与纵向电流呈二次方比例关系，而电流施加于 Berry 曲率偶极子方向。此外，我们还展示了我们的非线性 Hall 器件在无线微波检测和倍频方面的功能。这些发现将耦合的自旋和谷物理从 2D 系统扩展到 3D 系统，并为探索体 NLHE 的应用奠定了基础。
