Signatures of magnetism in zigzag graphene nanoribbons embedded in a hexagonal boron nitride lattice.

Zigzag edges of graphene are predicted to host magnetic electronic states, critical for spintronics, but an experimental confirmation of these magnetic conduction channels remains elusive. Here we report the signatures of magnetism in zigzag graphene nanoribbons (zGNRs) embedded in hexagonal boron nitride. Hexagonal boron nitride provides crucial edge stabilization, enabling the direct probing of this intrinsic magnetism. Scanning nitrogen-vacancy-centre microscopy initially confirmed magnetism in zGNR. Subsequently, an ~9-nm-wide zGNR transistor was fabricated with a sub-50-nm channel length. Magnetotransport measurements at 4 K revealed distinct Fabry-Pérot-like interference patterns, indicating coherent transport. A large, anisotropic magnetoresistance (~175 Ω, ~1.3%) was observed, persisting well above room temperature. These findings strongly corroborate the existence of robust magnetic ordering in the zGNR edge state. This hexagonal-boron-nitride-embedded zGNR system offers an effective platform for future graphene-based spintronic devices.