Perpendicular Néel Vector Detection of Monolayer Collinear Antiferromagnets with Spin-Layer Coupling

The precise detection of a perpendicular Néel vector in collinear antiferromagnetic (AFM) materials has long been expected for advancing two-dimensional AFM spintronics. Here, we proposed the perpendicular Néel vector detection using the layer Hall effect in collinear antiferromagnets down to the monolayer limit. Through materials screening, the Co₂S₂ is identified as a prototypical AFM monolayer with the spin-layer coupling and perpendicular magnetic anisotropy. Thanks to the electrically engineered layer-locked band edges and Berry curvatures from spin-layer coupling, a sizable layer-polarized anomalous Hall conductivity of σ_xy up to ∼110 S/cm is obtained in monolayer Co₂S₂. Intriguingly, the sign of σ_xy changes when the Néel vector is reversed, providing an efficient route for detecting the AFM order. Moreover, the achievement of the Néel vector detection via the layer Hall effect is further demonstrated in altermagnetic monolayer Ca(CoN)₂. The present findings open an avenue to explore the Néel vector detection for atomic-scale AFM materials and spintronic devices.