Strain tuning of the nonlinear anomalous Hall effect in MoS2 monolayer

TL;DR

This paper investigates how uniaxial strain influences the nonlinear anomalous Hall effect in MoS2 monolayer, revealing tunable Hall angles and birefraction-like phenomena linked to Berry curvature dipoles, with implications for 2D electronic devices.

Contribution

It demonstrates strain-induced control of the nonlinear Hall effect and introduces birefraction-like behavior in MoS2 monolayers, expanding understanding of strain effects in 2D materials.

Findings

Strain modifies the magnitude of the nonlinear AHE.

The nonlinear Hall angle can be tuned by strain.

Birefraction-like phenomena are observed in monolayer MoS2.

Abstract

Due to the time reversal symmetry, the linear anomalous Hall effect (AHE) usually vanishes in MoS2 monolayer. In contrast, the nonlinear AHE plays an essential role in such system when the uniaxial strain breaks the C3v symmetry and eventually results in the nonzero Berry curvature dipole (BCD). We find that not only the magnitude of the AHE but also the nonlinear Hall angle can be tuned by the strain. Especially the nonlinear Hall angle exhibits a deep relationship which is analogy to the birefraction phenomenon in optics. It actually results from the pseudotensor nature of the BCD moment. Besides the ordinary positive and negative crystals in optics, there are two more birefraction-like cases corresponding to an imaginary refraction index ratio in monolayer MoS2. Our findings shed lights on the strain controlled electronic devices based on the two-dimensional (2D) materials with BCD.