Symmetry breaking and magnetically tuned anisotropic behavior in WSe₂/CrOCl/ReSe₂ heterostructures

Van der Waals heterostructures are emerging as a versatile platform for next-generation electronic and photonic devices due to their unique anisotropic properties. While extensive studies have addressed symmetry breaking in transition metal dichalcogenides (TMDCs), the influence of magnetic fields on optical anisotropy remains underexplored. Here, we present an isotropic/magnetic/anisotropic heterostructure composed of WSe₂, ReSe₂, and the magnetic material CrOCl, which induces in-plane anisotropy in monolayer WSe₂. Density functional theory (DFT) calculations reveal significant modulation of the in-plane charge density of WSe₂ by ReSe₂ and CrOCl, providing direct evidence of anisotropic electronic behavior. Photoluminescence measurements at 300 and 1.7 K show strongly linearly polarized exciton emission, with magnetic fields ranging from −9 to 9 T modulating the anisotropy. Specifically, the anisotropy is enhanced by up to 28.34% and reduced by 40.37% under different magnetic field directions. Temperature variations also influence the linear polarization, achieving anisotropy ratios of 2.34 for neutral excitons and 1.77 for charged excitons. These results underscore a robust approach to dynamically tuning optical anisotropy via magnetic and thermal controls, paving the way for advanced polarization-sensitive optoelectronic applications.