Two‐Dimensional van der Waals Antiferromagnets: Fabrication, Probes, Control, and Applications

Two‐dimensional van der Waals antiferromagnets (2D vdW AFMs) have emerged as promising platforms for next‐generation spintronic and quantum devices. Compared with ferromagnetic (FM) counterparts, AFMs exhibit compensated spin configurations, eliminating stray fields while enabling ultrafast spin dynamics, high integration density, and resilience to magnetic perturbations. Advances in layer‐controlled synthesis, heterostructure assembly, and advanced magnetic characterization techniques have enabled the exploration and manipulation of antiferromagnetic (AFM) order down to the atomic limit, where reduced dimensionality and interlayer coupling generate magnetic phenomena. This review summarizes recent progress in 2D vdW AFMs, within a magnetic‐state engineering framework linking material preparation, order identification, magnetic control, and functional utilization. We compare top–down and bottom–up fabrication strategies and assess magnetotransport, optical and spectroscopic techniques, nitrogen‐vacancy magnetometry, and x‐ray‐based probes for resolving spin configurations, magnetic anisotropy, magnetic domains, and phase transitions, and highlight control of AFM states via fields, interfacial engineering, and chemical modification. We further review applications in spin‐filter tunneling, topological quantum states, opto‐spintronics, terahertz (THz) spin dynamics, and layered altermagnets. Finally, we outline challenges in ordering temperatures, environmental stability, wafer‐scale synthesis, reproducible control and readout, and device integration. Addressing these issues is essential for advancing functional spintronic and quantum technologies.