Parity-dependent coupling of molecular spin chains to a superconductor

Parity-dependent coupling of molecular spin chains to a superconductor

Collective behaviour in quantum materials can produce excitations carrying only a fraction of the quantum numbers of their constituents. A notable case occurs in chains of spin-1 units1, in which a topological gap protects the interior of the chain, whereas spin-1/2 states, half the spin of the units that form it, emerge at the ends2. In short chains, these fractional edge spins couple to each other and their topological protection makes them at…