Nonlinear Anomalous Hall Effect and Nonlinear Photocurrent Responses in 2D Topological Materials

Noninvasive detection and efficient control of electric and magnetic orders in 2D quantum materials is crucial for the development of 2D quantum electronics. We present our recent theoretical work on nonlinear response and sensing of 2D topological materials [1,2,3]. Few-layer WTe₂ holds out-of-plane polarization and can be switched via interlayer sliding under electric field. Ferroicity-driven switching of nonreciprocal nonlinear photocurrent [4] such as ferroelectric nonlinear anomalous Hall effect can be achieved in WTe₂ by utilizing intrinsic coupling among susceptibility, symmetry, and quantum geometry of electronic states [1], paving theoretical foundation for nonlinear memory such as Berry curvature memory recently demonstrated in trilayer WTe₂ [2]. We discuss nonlinear photocurrent in PT-symmetry magnetic topological quantum materials [3]. Magnetic photocurrent can be magnetically and electrically switched in bilayer AFM MnBi₂Te₄, highly tunable down to a few THz regime with rich THz and magneto-optoelectronic applications. References: [1] npj Comput. Mater. 5, 119 (2019). [2] Nat. Phys. 16, 1028-1034 (2020). [3] arXiv:2006.13573 (2020). [4] Sci. Adv. 5, eaav9743 (2019).