Nonlinear magneto-optical response across a van Hove singularity in a noncentrosymmetric magnetic Weyl semimetal

We investigate the nonlinear magneto-optical response in noncentrosymmetric magnetic Weyl semimetals featuring a quadratic tilt, focusing particularly on the influence of the van Hove singularity (VHS). In the absence of a magnetic field, the second-order nonlinear Drude conductivity components exhibit inflection or dip behavior across the VHS. In contrast, the second-order nonlinear anomalous Hall conductivity, primarily governed by the Berry curvature dipole, manifests a subtle plateaulike structure. As the tilt strength increases, the VHS energy rises, thereby amplifying the VHS-induced characteristics within these second-order conductivity components. However, we show that in the presence of a magnetic field, the resultant magnetic moment suppresses nonlinear electron transport while enhancing nonlinear hole transport. This effect serves to mitigate the impact of the VHS, resulting specifically in an asymmetric peak or a kinklike structure in the magnetic-field-induced contribution to the second-order nonlinear conductivity near the Weyl nodes. These findings provide insights into the intricate interplay among the VHS, Berry curvature, and magnetic moment in nonlinear magneto-optical transport through noncentrosymmetric magnetic Weyl semimetals.