Disorder Scattering Induced Large Room Temperature Nonlinear Anomalous Hall Effect in a Semiconductor CdGeAs₂

The nonlinear Hall effect (NLHE) with time-reversal symmetry has emerged as a transformative phenomenon within the Hall effect family, attracting significant interest due to its profound implications for both fundamental physics and technological applications. While prior studies have predominantly focused on NLHE in 2D materials, advancements in practical applications have been constrained by low operating temperatures and limited responsivity, typically below 10⁻⁴ m/V. Achieving significant responsivity at room temperature (RT) in 3D systems has proven challenging, particularly for scattering-induced NLHE. Here, the discovery of disorder scattering-induced NLHE in chalcopyrite-type CdGeAs₂ bulk single crystals is reported, demonstrating a remarkable responsivity of up to 10⁻³ m/V at RT. The 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 and nonlinear Hall conductivity scaling analyses, disorder scattering is identified as the dominant mechanism for the NLHE in CdGeAs₂. Leveraging the observed strong responsivity of NLHE at RT, its broadband electronic frequency mixing capability in the MHz range is further demonstrated. This work sets the foundation for integrating scattering-induced NLHE in 3D materials into very high-frequency mixing technologies.