Disorder scattering induced large room temperature nonlinear anomalous Hall effect in a semiconductor CdGeAs₂

Nonlinear Hall effect (NLHE) with time-reversal symmetry has emerged as a transformative phenomenon with potential for new physical insights and applications. Most previous studies have focused on 2D systems, but their applications are limited by low operating temperatures and small responsivity (< 10^-4 m/V). Achieving strong NLHE signals at room temperature in 3D systems remains difficult. In this talk, we report the discovery of disorder scattering-induced NLHE in chalcopyrite-type CdGeAs₂ bulk single crystals, demonstrating a remarkable responsivity of up to 10^-3 m/V at room temperature. Our studies reveal that NLHE not only facilitates ac-driven second harmonic and rectification Hall responses but also induces an exceptionally large anomalous Hall angle. Through band structure measurements by ARPES, DFT calculations, as well as symmetry analysis and nonlinear Hall conductivity scaling analysis, we identify disorder scattering as the dominant mechanism for the NLHE in CdGeAs₂. Leveraging the observed strong responsivity of NLHE at room temperature, we further demonstrate its broadband electronic frequency mixing capability in the MHz range. This work sets the foundation for integrating scattering-induced NLHE into three-dimensional materials for very high-frequency mixing technologies.

The study at PSU 2DCC-MIP is supported by NSF Cooperative Agreement No. DMR-2039351.