Faithfully Simulating Near-Term Quantum Repeaters

Quantum repeaters have long been established to be essential for distributing entanglement over long distances. Consequently, their experimental realization constitutes a core challenge of quantum communication. However, there are numerous open questions about implementation details for realistic near-term experimental setups. In order to assess the performance of realistic repeater protocols, here we present ReQuSim, a comprehensive Monte Carlo–based simulation platform for quantum repeaters that faithfully includes loss and models a wide range of imperfections such as memories with time-dependent noise. Our platform allows us to perform an analysis for quantum repeater setups and strategies that go far beyond known analytical results: This refers to being able to both capture more realistic noise models and analyze more complex repeater strategies. We present a number of findings centered around the combination of strategies for improving performance, such as entanglement purification and the use of multiple repeater stations, and demonstrate that there exist complex relationships between them. We stress that numerical tools such as ours are essential to model complex quantum communication protocols aimed at contributing to the quantum Internet.7 MoreReceived 6 March 2023Revised 8 November 2023Accepted 23 January 2024DOI:https://doi.org/10.1103/PRXQuantum.5.010351Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasQuantum communicationQuantum entanglementQuantum repeatersQuantum Information, Science & Technology