Control over Berry Curvature Dipole with Electric Field in WTe2

TL;DR

This paper demonstrates how applying an electric field in WTe2 can generate and control Berry curvature dipole, overcoming symmetry constraints and enabling new nonlinear quantum device functionalities.

Contribution

The study shows that a dc electric field can induce and manipulate Berry curvature dipole in WTe2, breaking symmetry restrictions and providing a method to control nonlinear quantum effects.

Findings

Berry curvature dipole can be generated by electric field in WTe2.

The dipole shows a linear relationship with the applied electric field.

The polarization of the Berry curvature can be reversed by changing the electric field polarity.

Abstract

Berry curvature dipole plays an important role in various nonlinear quantum phenomena. However, the maximum symmetry allowed for nonzero Berry curvature dipole in the transport plane is a single mirror line, which strongly limits its effects in materials. Here, via probing the nonlinear Hall effect, we demonstrate the generation of Berry curvature dipole by applied dc electric field in WTe2, which is used to break the symmetry constraint. A linear dependence between the dipole moment of Berry curvature and the dc electric field is observed. The polarization direction of the Berry curvature is controlled by the relative orientation of the electric field and crystal axis, which can be further reversed by changing the polarity of the dc field. Our Letter provides a route to generate and control Berry curvature dipole in broad material systems and to facilitate the development of nonlinear quantum devices.