Artificially Creating Emergent Interfacial Antiferromagnetism and Its Manipulation in a Magnetic van der Waals Heterostructure.

van der Waals (vdW) magnets, with their two-dimensional (2D) atomic structures, provide a unique platform for exploring magnetism on the nanoscale. Although there have been numerous reports on their diverse quantum properties, the emergent interfacial magnetism─artificially created at the interface between two layered magnets─remains largely unexplored. This work presents observations of such emergent interfacial magnetism at the ferromagnet-antiferromagnet interface in a vdW heterostructure. We report the discovery of an intermediate Hall resistance plateau in the anomalous Hall loop indicative of emergent interfacial antiferromagnetism fostered by the heterointerface. This plateau can be stabilized and further manipulated under varying pressures but collapses at high pressures over 10 GPa. Our theoretical calculations reveal that charge transfer at the interface is pivotal in establishing the interlayer antiferromagnetic spin-exchange interaction. This work illuminates the previously unexplored emergent interfacial magnetism at a vdW interface comprising a ferromagnetic metal and an antiferromagnetic insulator and highlights its gradual evolution under increasing pressure. These findings enrich the portfolio of emergent interfacial magnetism and support further investigations of vdW magnetic interfaces and the development of next-generation spintronic devices.