In recent years, atomically thin materials—crystals only a few atoms thick—have attracted growing attention because they can exhibit physical properties that do not appear in conventional bulk materials. Among them, atomically thin magnetic materials are particularly intriguing, as they can host unconventional magnetic states and offer new possibilities for spin-based electronic technologies.

In a Nature Materials study, researchers investigated the photocurrent response of a bilayer atomically thin antiferromagnet. In this material, spins are aligned within each atomic layer, while the spin orientations of the top and bottom layers are opposite. Depending on the relative spin configuration between the two layers, the system exhibits two distinct antiferromagnetic (AFM) states.

To explore how these magnetic states interact with light, the researchers fabricated devices by attaching electrodes to bilayer samples and illuminated the center of the material, away from the electrodes. They measured both the zero-bias photocurrent and current-voltage characteristics under illumination.