Spontaneous Topological Hall Effect in Intercalated Co_1/3TaS₂ Nanoflakes with Non‐Coplanar Antiferromagnetic Order

Abstract The recently discovered long‐range topological spin textures exhibit spontaneous Hall effects, which offer a breakthrough solution to the challenge of write‐in and readout of spin information in antiferromagnets. Despite this advancement, the implementation of such long‐range magnetic orders in single‐crystal nanoflakes remains limited, which can otherwise enhance the design flexibility of heterostructures and open new possibilities for next‐generation ultracompact, high‐speed, and low‐power spintronic devices. Here, air‐stable intercalated Co 1/3 TaS 2 single‐crystal nanoflakes are reported, demonstrating two magnetic phase transitions and a potential charge density wave phase transition. Transport measurements confirmed the persistence of non‐coplanar antiferromagnetic order in exfoliated Co 1/3 TaS 2 nanoflakes, characterized by a spontaneous topological Hall effect with rectangular shape and moderate coercive fields. The underlying mechanisms of the two magnetic phase transitions, as well as the anomalous Hall effect resulting from skew scattering observed above the Néel temperature, are investigated. Furthermore, the successful integration of Co 1/3 TaS 2 nanoflake into van der Waals heterostructure underscores the potential for diverse device applications. This study enhances the understanding of non‐coplanar antiferromagnetic order and advances the field of antiferromagnetic spintronics.