Advancements in Nonlinear Hall Effect Through Optical Techniques

Recent research has unveiled a significant advancement in the understanding of the nonlinear Hall effect, particularly under the influence of light. The study, titled "Light-enhanced nonlinear Hall effect," authored by Fang Qin, Rui Chen, and Ching Hua Lee, explores how the Hall response in materials with broken inversion symmetry can deviate from its expected quantized value. This deviation is attributed to a phenomenon known as the Berry curvature dipole (BCD), which is typically small and challenging to observe without precise external conditions.

The researchers have developed innovative optical driving and quench protocols that allow for direct access to large BCD and nonlinear Hall responses. By varying the amplitude of an incident circularly polarized laser, they can induce a topological transition between normal and Chern insulator phases. This technique enables the unlocking of nonlinear Hall currents that can be comparable to or even exceed linear Hall contributions.

This research not only provides a deeper understanding of the nonlinear Hall effect but also opens avenues for the controlled engineering of electronic properties in various materials. The findings are expected to have broad implications across different Hall materials, potentially impacting the development of advanced electronic devices and materials science. The full paper can be accessed at arXiv:2401.18038.