Designing Antiferromagnetic Spin-1/2 Chains in Janus Fullerene Nanoribbons

We design antiferromagnetic spin-1/2 chains in fullerene nanoribbons by introducing extra C$_{60}$ cages at one of their edges. The resulting odd number of intermolecular bonds induces an unpaired $\pi$-electron and hence a quantised magnetic moment in otherwise non-magnetic nanoribbons. We further reveal the formation of an antiferromagnetic ground state upon the linear arrangement of spin-1/2 C$_{60}$ cages that is insensitive to the specific structural motifs. Compared with graphene nanoribbons, Janus fullerene nanoribbons may offer an experimentally more accessible route to magnetic edge states with atomic precision in low-dimensional carbon nanostructures, possibly serving as a versatile nanoarchitecture for scalable spin-based devices and the exploration of many-body quantum phases.