A hybrid-system approach for W state and cluster state generation

Here we demonstrate an efficient scheme for W state and cluster state generation based on the hybrid-system where nitrogen-vacancy centers are coupled to microcavities. In our proposed scheme, entanglement between solid-state qubits can be generated with the assistance of an ancillary photon. We also discuss the efficiency of the entanglement generation protocols and generalize them to multi-qubit cases. With current and near-future technology, the entanglement of nitrogen-vacancy centers can be achieved and our scheme can further be used for quantum information processing and long-distance quantum communication.