Proximity‐Driven Non‐Volatile Spin and Valley Control in a Van Der Waals Antiferromagnetic Heterostructure

The integration of non-volatile spin and valley control in 2D quantum systems remains a pivotal challenge for spintronic and valleytronic functionalities. Here, we demonstrate persistent spin and valley polarizations in a van der Waals heterostructure comprising bulk antiferromagnetic CrPS₄ and monolayer MoSe₂, achieved via interfacial magnetic proximity effects. The 1L-MoSe₂/bulk-CrPS₄ heterostructure exhibits non-volatile hysteresis in chiral photoluminescence (PL), directly linked to the antiferromagnetic ordering of bulk-CrPS₄. This helicity of PL persists at zero field, enabled by the spin-polarized charge transfer from the K valley in the MoSe₂ monolayer to the conduction band of CrPS₄, breaking the valley degeneracy without external stimuli. Remarkably, the PL helicity switches surprisingly at a magnetic field of ∼ 0.5 T, a 17-fold smaller than the spin-flip field of ∼8.5 T in bulk CrPS₄. Our work establishes bulk antiferromagnet-based heterostructure as a robust platform for low-energy, magnetically tunable quantum devices, bridging the gap between the transient valleytronic phenomena and practical non-volatile applications.