Multiuser Entanglement Distribution in Quantum Networks Using Multipath Routing

Quantum networks facilitate numerous applications such as securecommunication and distributed quantum computation by performing entanglementdistribution. Multi-user quantum applications where quantum information isshared between multiple users require access to a shared multipartite statebetween the users. We consider the problem of designing protocols fordistributing such states, at an increased entanglement rate. We propose three protocols that increase the entanglement rate of multi-userapplications by leveraging multipath routing. The protocols are evaluated onquantum networks with NISQ constraints, including limited quantum memories andprobabilistic entanglement generation. Monte Carlo simulation results show thatthe developed protocols achieve an exponential speedup of entanglement ratecompared to single-path routing techniques, with a maximum speedup of fourorders of magnitude for the cases studied. The speedup was also found toimprove for larger sets of users. When the protocols were tested in scaled-downreal-world topologies, it was found that topology can have a significant effecton the achievable entanglement rates, with one order of magnitude differencebetween topologies. Finally, we find that the benefits of multipath routing area maximum for short quantum memory decoherence times, and intermediate valuesof entanglement generation probability. Hence the protocols developed canbenefit NISQ quantum network control and design.