Giant non-linear anomalous Hall effect in three-dimensional T_d-MoTe₂

While the anomalous Hall effect can manifest even without an external magnetic field, time reversal symmetry is nonetheless still broken by the internal magnetization of the sample. Recently, it has been shown that certain materials without an inversion center allow for a nonlinear type of anomalous Hall effect whilst retaining time reversal symmetry. Here, the application of a harmonic longitudinal current or voltage generates a second harmonic component in the transverse direction. The effect may arise from either Berry curvature properties intrinsic to the material’s band structure or through various asymmetric scattering mechanisms. In this talk, I will be presenting our observation of an extremely large c-axis nonlinear anomalous Hall effect in the non-centrosymmetric Td phase of MoTe2 without intrinsic magnetic order, whose strength obeys a universal scaling with sample conductivity.