Robust scalable architecture for a hybrid spin-mechanical quantum entanglement system

Practical quantum information technique requires a large scalable quantum network. We proposed a hybrid system for deterministic scalable spin entanglement network based on nitrogen-vacancy (NV) centers in diamond coupling with carbon nanotube. The fault-tolerant entangled gate between two remote NV centers can be realized with vibrating nanotube assisted spin-spin interaction with current experimental technology. This interaction can be directly generalized to multi-NV-center entanglement architecture. Moreover, the effects of the single spin dephasing (SSD) and spin cross relaxation (SCR) on this state generation process were analyzed in detail. We found that the decay rate scales as ${N}^{2}$, corresponding to the number of independent decoherence channels. However, by employing dressed state protection and independent tunable interaction method, SSD and SCR can be mitigated efficiently and the decay rate of the generated multi-NV-center entanglement scales as $N$, which boosts the size of the entanglement network up to hundreds of qubits. Such a hybrid quantum system compatible with current topological protection provides a useful platform for the investigation of quantum computation.