Magnetically Reconfigurable Noncollinear Excitonic Polarization in a MoSe 2 /CrOCl/Fe 3 GaTe 2 Heterostructure

Van der Waals (vdW) heterointerfaces provide a versatile platform for tailoring polarization‐resolved excitonic emission in 2D semiconductors, offering new opportunities for polarization‐encoded photonic functionalities. However, the realization of distinct and externally reconfigurable polarization orientations for coexisting excitonic states within a single magnetic heterostructure remains largely unexplored. Here we demonstrate magnetically reconfigurable exciton polarization in a MoSe 2 /CrOCl/Fe 3 GaTe 2 vdW heterostructure, arising from the combined effects of interfacial symmetry breaking and magnetically mediated interfacial coupling. Polarization‐resolved photoluminescence measurements reveal pronounced in‐plane anisotropy for both neutral excitons (X 0 ) and trions (T), with strongly non‐collinear polarization axes. Near the spin‐flop transition of CrOCl, the emission polarization undergoes an abrupt ∼ 90°rotation under an applied magnetic field, generating bistable polarization states that allow optical readout of magnetic phase evolution and dual‐channel polarization encoding. A further reorientation across the Néel temperature highlights the intimate coupling between magnetic order and lattice symmetry at the heterointerface. First‐principles calculations attribute the emergent anisotropy to anisotropic charge redistribution in MoSe 2 . These findings establish magnetic vdW heterointerfaces as a route to reconfigurable multi‐exciton polarization control and magnetic‐field‐tunable polarization encoding in 2D materials.