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

ABSTRACT 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 CrPS 4 and monolayer MoSe 2 , achieved via interfacial magnetic proximity effects. The 1L‐MoSe 2 /bulk‐CrPS 4 heterostructure exhibits non‐volatile hysteresis in chiral photoluminescence (PL), directly linked to the antiferromagnetic ordering of bulk‐CrPS 4 . This helicity of PL persists at zero field, enabled by the spin‐polarized charge transfer from the K valley in the MoSe 2 monolayer to the conduction band of CrPS 4 , 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 CrPS 4 . 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.