Scaling network topologies for multi-user entanglement distribution

Future quantum internet relies on large-scale entanglement distribution. Quantum decoherence is a significant obstacle in large-scale networks, which otherwise perform better with multiple paths between the source and destination. We propose a new topology, a connected tree, with a significant number of redundant edges to support multi-path routing of entangled pairs. We qualitatively analyze the scalability of quantum networks to maximum user capacity in decoherence for different topologies. Our analysis shows that thin-connected tree networks can accommodate a larger number of user pairs while maintaining a high-routing environment, resulting in less dependence on quantum memories for routing than distributed lattice or P-2-P topologies, thus leading to robustness against decoherence and better key generation rates among multiple communicating parties in quantum key distribution.