Utilizing Rydberg superatoms to fuse the W state and the GHZ state

Abstract

Multiparticle entanglement has important applications in quantum information and quantum computing. Here, we propose two schemes to fuse large-scale entangled W states and GHZ states. In the first fusion scheme, we send two Rydberg superatoms that belong to an n particle W state and an m particle W state, respectively, into a vacuum cavity; an (n+m−2) particle W state can be obtained by detecting the state of the superatoms after the interaction. In the second fusion scheme, we send two Rydberg superatoms into two separate cavities; with the assistance of a circularly polarized photon, we can obtain a (k+l) particle GHZ state after detecting the state of the photon. The numerical simulation analysis shows that both schemes are robust against the spontaneous emission of superatoms and the decay of the cavity. The feasibility analysis indicates that these two schemes can be realized in experiments.