Evolution of the Berry curvature dipole in uniaxially strained bilayer graphene

TL;DR

This paper investigates how uniaxial strain affects the Berry curvature dipole in bilayer graphene, emphasizing the importance of detailed tight-binding models for accurate predictions of nonlinear Hall effects.

Contribution

It demonstrates the strain and doping dependence of the Berry curvature dipole using a comprehensive tight-binding approach, highlighting the limitations of continuum models.

Findings

Uniaxial strain induces a finite Berry curvature dipole in bilayer graphene.

Longer-range interlayer hoppings significantly influence the Berry curvature dipole.

Out-of-plane compression broadens Dirac cones, enhancing the nonlinear Hall response.

Abstract

While in pristine bilayer graphene the Berry curvature dipole (BCD), a necessary ingredient for the nonlinear anomalous Hall effect, is zero, uniaxial strain can give rise to finite BCD. We investigate this by using a tight-binding (TB) approach build on the Slater-Koster parameterization to capture lattice deformation effects often missed by continuum models. We demonstrate that the BCD's evolution with strain and doping is highly sensitive to the choice in parameterization, particularly when including the longer range interlayer skew hoppings. Additionally, out-of-plane compression enhances the response by broadening the Dirac cones. These findings benchmark low-energy continuum models and highlight the necessity of realistic tight-binding models for accurately predicting strain-engineered Hall effects in bilayer graphene.