Quantum entanglement is a key resource in quantum information processing. In this paper, we propose a scheme for preparing a cluster entangled state by means of multiple nitrogen vacancy centers and microtoroidal resonator coupled systems. The scheme employs an input–output process and single-photon interference, without any other auxiliary entanglement particles or classical communication. Considering the current experimental technology, the scheme will be implemented and has an important role in the preparation of cluster entangled state by means of nitrogen vacancy centers and microtoroidal resonator coupled systems.
We propose a potentially practical scheme to entangle negatively charged nitrogen-vacancy (N-
V) centers in distant diamonds. Each diamond is supposed to be fixed on the exterior surface of a microtoroidal resonator, and the single-photon input-output process---a currently available technique---could entangle separate N-
V centers in a scalable fashion. The feasibility of our scheme and the experimental challenge are discussed by considering currently available techniques for qualified N-
V centers and cavities.