As a crucial concept in magnetism and spintronics, exchange bias (ExB) measures the asymmetry in the hysteresis loop of a pinned ferromagnet (FM)/antiferromagnet (AFM) interface. Previous studies are mainly focused on FM/AFM heterostructures composed of conventional bulk materials, whose complex interfaces prohibit precise control and full understanding of the phenomenon. Here, the enabling power of 2D magnets is exploited to demonstrate the emergence, non‐aging, extendability, and rechargeability of ExB in van der Waals Fe3GeTe2 homostructures, upon moderate pressuring. The emergence of the ExB is attributed to a local stress‐induced FM‐to‐AFM transition, as validated using first‐principles calculations, and confirmed in magneto‐optical Kerr effect and second harmonic generation measurements. It is also observed that, negligible ExB aging before the training effect suddenly takes place through avalanching, pronounced delay of the avalanche via timed pressure repetition (extendability), ExB recovery in the post‐training sample upon refreshed pressuring (rechargeability), and demonstrate its versatile tunability. These striking findings offer unprecedented insights into the underlying principles of ExB and its training, with immense technological applications in sight.
2D van der Waals (vdW) antiferromagnets have received intensive attention due to their terahertz resonance, multilevel magnetic-order states, and ultrafast spin dynamics. However, accurately identifying their magnetic configuration still remains a challenge owing to the lack of net magnetization and insensitivity to external fields. In this work, the Néel-type antiferromagnetic (AFM) order in 2D antiferromagnet VPS 3 with the out-of-plane anisotropy, which is demonstrated by the temperature-dependent spin-phonon coupling and second-harmonic generation (SHG), is experimentally probed. This long-range AFM order even persists at the ultrathin limit. Furthermore, strong interlayer exciton-magnon coupling (EMC) upon the Néel-type AFM order is detected based on the monolayer WSe 2 /VPS 3 heterostructure, which induces an enhanced excitonic state and further certifies the Néel-type AFM order of VPS 3 . The discovery provides optical routes as the novel platform to study 2D antiferromagnets and promotes their potential applications in magneto-optics and opto-spintronic devices.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.