Engineering nonlinear Hall effect in bilayer graphene/black phosphorus heterostructures

TL;DR

This paper demonstrates how stacking bilayer graphene with black phosphorus induces a nonlinear Hall effect that persists at room temperature, with sign reversals controlled by an electric displacement field, highlighting symmetry engineering's potential for quantum devices.

Contribution

It introduces a method to engineer nonlinear Hall effects in van der Waals heterostructures through symmetry breaking, enabling room-temperature quantum device applications.

Findings

NLHE persists up to room temperature.

Sign reversals of NLHE are controlled by displacement fields.

Sign reversal linked to Berry curvature dipole and extrinsic scatterings.

Abstract

Two-dimensional van der Waals materials offer a highly tunable platform for generating emergent quantum phenomena through symmetry breaking. Stacking-induced symmetry breaking at interfaces provides an effective method to modulate their electronic properties for functional devices. Here, we strategically stack bilayer graphene with black phosphorus, a low-symmetry semiconductor, to break the symmetries and induce the nonlinear Hall effect (NLHE) that can persist up to room temperature. Intriguingly, it is found the NLHE undergoes sign reversals by varying the electrical displacement field under fixed carrier density. The scaling analysis reveals that the sign reversal of the NLHE is contributed from both the Berry curvature dipole (BCD) and extrinsic scatterings. The displacement field-induced sign reversal of the BCD indicates asymmetric distributions of Berry curvature hot spots across different Fermi pockets in bilayer graphene. Our findings suggest that symmetry engineering of van der Waals heterostructures is promising for room-temperature applications based on nonlinear quantum devices, such as high-frequency rectifiers and wireless charging.