In-situ entanglement generation based on rare-earth quantum memory coupled to a nonlinear cavity (Part II: theoretical analysis)

The performance of conventional spin-ensemble quantum memories are limited by various imperfections associated with transferring photons to the matter-based memory. In this work, we study a novel architecture where a rare-earth-based spin memory directly couples to an entanglement-generating cavity photon source. In this second talk of the series, I will present our theoretical analysis of the generated spin-photon entangled state. I will illustrate that our architecture implicitly generates tripartite entanglement between two photonic outputs and the spins. We find that the entanglement generation and memory retrieval processes require different optimal system parameters. Even in the partly optimized situation, however, I will show that considerable entanglement can be distributed between remote memories. By using appropriate protocols, our system can generate entanglement for both discrete- and continuous-variable quantum information processing schemes.