Chip-mediated manipulation of photonic quantum skyrmions

Quantum skyrmions are attracting much interest owing to their topological robustness, which offers a route to address noise and loss in quantum systems. The toolkit for their creation has advanced recently, enabling quantum skyrmions to be generated in bulk systems as entangled states and on chip as single-photon states. However, methods for generating on-chip entangled skyrmions, as well as for their reconfigurable manipulation and controlled interfacing with single-photon skyrmions, remain elusive. Here we demonstrate entangled skyrmions and their manipulation on chip with an integrated silicon nitride nanophotonic platform. The skyrmion topology is coherently encoded in a local single-photon spin-textured quantum state, which is subsequently transferred into a non-local skyrmion topology shared between two entangled photons. Throughout the transfer process, the topology remains preserved under background noise and different types of disturbance, even after the entanglement vanishes. This establishes a quantum-topology-enabled transfer scheme beyond entanglement, which reveals a fundamentally enhanced resilience that outperforms conventional entanglement-assisted quantum state transfer. This approach serves as a step towards building robust quantum interconnects and advancing distributed quantum information technology mediated by topology. Although photonic quantum skyrmions can be generated as entangled or single-photon states, a means to switch between the two is required for quantum information processing. Now, entangled skyrmions and their manipulation on chip is realized.