Superconductivity and magnetism are traditionally viewed as competing phenomena, yet their controlled coexistence can give rise to rich and unexpected quantum effects. Van der Waals materials have recently emerged as an attractive platform for exploring this interplay, enabling clean and tunable superconductor–magnet hybrids. Here, we report the first realization of a NbSe₂-based Josephson junction incorporating an antiferromagnetic insulator, NiPS₃. The junction behaves as a superconducting quantum interference device (SQUID)—a key building block of quantum sensors—without requiring conventional lithographic fabrication. Remarkably, this SQUID-like behavior survives in strong in-plane magnetic fields of at least 6 tesla. Supported by microscopic modeling, we attribute this behavior to interference between distinct, localized superconducting transport channels formed at the edges of the junction, arising from the interplay between superconductivity and the antiferromagnetic texture of NiPS₃. Our results show that heterostructures combining antiferromagnetic insulators and superconductors can host robust and unconventional superconducting transport, even in strong magnetic fields. These findings highlight van der Waals antiferromagnet–superconductor systems as a promising platform for studying new superconducting phenomena and for developing superconducting devices. [Full Article]
