Electro-optic Kerr Effect Induced by Nonlinear Transport in monolayer WTe2

TL;DR

This paper proposes and analyzes an electro-optic Kerr effect induced by nonlinear Hall effect in monolayer WTe2, offering a new optical method to probe nonlinear topological phenomena in non-magnetic materials.

Contribution

It introduces the concept of NLHE-induced electro-optic Kerr effect as a novel optical probe for nonlinear Hall effects in non-magnetic systems, specifically in monolayer WTe2.

Findings

EOKE signal in WTe2 is mainly governed by Berry curvature dipole.

Kerr angle shows temporal oscillations at different optical frequencies.

EOKE enables time-resolved detection of nonlinear Hall effects.

Abstract

The nonlinear Hall effect (NLHE) can induce optical anisotropy by modifying a material's dielectric tensor, presenting opportunities for novel characterization and device applications. While the magneto-optical Kerr effect (MOKE) probes the linear Hall effect (LHE) in magnetic materials, an analogous optical probe for NLHE in non-magnetic, time-reversal symmetric systems remains highly desirable. Here, we theoretically propose and investigate an NLHE-induced Electro-optic Kerr Effect (EOKE) as such a probe. Focusing on monolayer (ML) WTe$_2$, a prototypical NLHE material, our analysis considers contributions from Berry curvature dipole (BCD), Drude, injection, and shift mechanisms. We demonstrate that the EOKE signal in WTe$_2$ is predominantly governed by the BCD. Furthermore, the Kerr angle exhibits temporal oscillations at different optical frequencies, suggesting EOKE as a promising route for the time-resolved detection of NLHE and the dynamic investigation of material topology.