Magnetic Proximity Effect and Valley Manipulation in 2D CrSBr/TMD Heterostructures

Two-dimensional magnetic semiconductors integrated into van der Waals heterostructures provide a promising platform for engineering spintronic and valleytronic functionalities through magnetic proximity effects. Here, we construct van der Waals heterostructures composed of monolayer or few-layer antiferromagnetic semiconductor CrSBr with in-plane magnetism and monolayer nonmagnetic transition metal dichalcogenides (TMDs, such as WSe ₂ and MoSe ₂ ). Pronounced valley-contrasting photoluminescence from monolayer TMDs emerges when the temperature is below the Néel temperature of CrSBr, in spite of their pristinely orthogonal spin alignment. Ultrafast pump-probe spectroscopy combined with theoretical calculations reveals that this emergent phenomenon originates from magnetic proximity effects and spin-selective interlayer charge transfer. Notably, the degree of circularly polarized photoluminescence strongly depends on the odd-even layer number of CrSBr, reflecting its intrinsic antiferromagnetic nature. These results deepen the understanding of magnetic proximity effects in two-dimensional magnetic heterostructures and provide guidance for designing multifunctional devices for spintronics, valleytronics, and quantum photonics.