Second-order nonlinear Hall effect in a type-II Weyl semimetal NbIrTe₄

Observations of nonlinear Hall effects (NLHE) and their connection to crystal symmetries broaden our understanding of how quantum geometrical quantities, such as the Berry curvature, influence material properties. While both quantum geometrical quantities and the electronic band structure play crucial roles in NLHE, there the correlation between them remains underexplored. In this study, we report the second-order nonlinear hall response in NbIrTe₄, measured from 2 K to room temperature, with a notable sign change in the Hall conductivity occurring at 150 K. Electrical transport measurements reveal transverse voltages exhibited at the second harmonic frequency of applied longitudinal AC current. Angle-dependent nonlinear Hall measurements highlights the influence of the crystal symmetry on this response. Analysis based on the angle-resolved photoelectron spectroscopy measurements suggests that the Berry curvature dipole, tuned by the partially occupied spin-orbit split bands, underpins the temperature-dependent responses. These findings deepen our understanding of the interplay between symmetry, geometrical quantities and NLHE.