Tunable In-Plane Anomalous Hall and Magneto-Optical Kerr Effects via Stacking Engineering in Two-Dimensional Magnets

The in-plane anomalous Hall effect (IPAHE) and magneto-optical Kerr effect (MOKE) have emerged as crucial functionalities in spintronics, yet their realization and control in two-dimensional (2D) magnetic systems remain challenging due to stringent symmetry constraints. In this study, based on symmetry analysis and first-principles calculations, we explore a general framework to achieve and modulate IPAHE and MOKE in 2D magnetic bilayers via interlayer sliding and spin-orientation engineering. Using ferromagnetic (FM) CrPSe₄ and antiferromagnetic (AFM) MPSe₃ (M = Mn and Cr) as prototype systems, we demonstrate that the modification of the stacking order and spin orientation can selectively manipulate symmetries, controlling the presence and sign of IPAHE and MOKE. Our findings establish a symmetry-protected coupling between spin, stacking order, and electronic response, providing a practical approach to achieve tunable IPAHE/MOKE. This work opens promising avenues for the development of next-generation magneto-optical devices and spintronic memory applications with enhanced functionality.