Berry curvature dipole in bilayer graphene with interlayer sliding

Abstract

Lowering lattice symmetry plays a pivotal role in generating a nonzero Berry curvature dipole. In this work, we demonstrate that introducing an interlayer sliding in bilayer graphene effectively breaks the inherent threefold rotational symmetry, thus giving rise to a nonzero Berry curvature dipole. Our numerical simulations also reveal the magnitude of the Berry curvature dipole can be further tuned by various parameters, including interlayer sliding distances and directions, as well as interlayer potential differences. We show even a tiny sliding distance of 0.02 nm can lead to a substantial Berry curvature dipole of about 10 nm in bilayer graphene, which is comparable to the values measured in transition metal dichalcogenides (TMDCs). Our work represents a new way to manipulate the topological properties of bilayer graphene, and this methodology can be extended into other two-dimensional systems, such as TMDCs with threefold rotational symmetry.