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

TL;DR

This study explores how van Hove singularities influence nonlinear magneto-optical responses in magnetic Weyl semimetals, revealing effects of tilt, magnetic field, and Berry curvature on conductivity behaviors.

Contribution

It uncovers the interplay between van Hove singularities, Berry curvature, and magnetic moments in shaping nonlinear optical responses in non-centrosymmetric magnetic Weyl semimetals.

Findings

VHS causes inflection or dip in nonlinear Drude conductivity.

Plateau-like structure in nonlinear anomalous Hall conductivity due to Berry curvature dipole.

Magnetic field suppresses electron transport but enhances hole transport, affecting VHS features.

Abstract

We investigate the nonlinear magneto-optical response in non-centrosymmetric 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 plateau-like structure. As the tilt strength increases, the VHS energy escalates, thereby amplifying the VHS-induced characteristics within these second-order conductivity components. However, in the presence of a magnetic field, we show that the resultant magnetic moment suppresses nonlinear electron transport while enhancing nonlinear hole transport. %both suppresses and notably enhances nonlinear magnetic-optical transport in the electron and hole regions, respectively. This effect serves to mitigate the impact of the VHS, resulting specifically in an asymmetric peak or a kinked-like structure in the magnetic field-induced contribution to the second-order nonlinear conductivity near the Weyl nodes. These findings provide new insights into the intricate interplay among the VHS, Berry curvature, and magnetic moment in nonlinear magneto-optical transport through non-centrosymmetric magnetic Weyl semimetals.