Poster:Electric field-tunable Berry curvature in WTe2

    Berry curvature, as one of the central topics in topological physics, plays an important role in various quantum transport phenomena, such as various Hall effects and Circular dichroism [1]. Recently, Berry curvature dipole (BCD), i.e., the dipole moment of Berry curvature [2] is proposed to be able to induce second-order nonlinear Hall effect. The nonzero BCD can lead to high-frequency rectifiers, wireless charging, and energy harvesting through the nonlinear Hall effect, promising for nonlinear quantum devices. However, the maximum symmetry allowed for nonzero BCD is a single mirror symmetry, unfavorable for real applications.

    Here, via probing the nonlinear Hall effect, we demonstrate the electric field-manipulated Berry curvature and BCD [3]. A linear dependence between the BCD 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 work provides a route to generate and control Berry curvature and BCD in broad material systems, and to facilitate the development of nonlinear quantum devices.

References

[1] D. Xiao, M.-C. Chang, and Q. Niu, Rev. Mod. Phys. 82, 1959 (2010).

[2] I. Sodemann and L. Fu, Phys. Rev. Lett. 115, 216806 (2015).

[3] X.-G. Ye, H. Liu, P.-F. Zhu, et al., Phys. Rev. Lett. 130, 016301 (2023).