End-to-End Capacities of Imperfect-Repeater Quantum Networks

Abstract

The optimal performance of a communication network is limited not only by the quality of point-to-point channels, but by the efficacy of its constituent technologies. Understanding the limits of quantum networks requires an understanding of both the ultimate capacities of quantum channels and the efficiency of imperfect quantum repeaters. In this work, using a recently developed node-splitting technique which introduces internal losses and noise into repeater devices, we present achievable end-to-end rates for noisy-repeater quantum networks. These are obtained by extending the coherent and reverse coherent information (single channel capacity lower bounds) into end-to-end capacity lower bounds, both in the context of single-path and multi-path routing. These achievable rates are completely general, and apply to networks composed of arbitrary channels arranged in general topologies. Through this general formalism, we show how tight upper-bounds can also be derived by supplementing appropriate single-edge capacity bounds. As a result, we develop tools which provide tight performance bounds for quantum networks constituent of channels whose capacities are not exactly known, and reveal critical network properties which are necessary for high-rate quantum communications. This permits the investigation of pertinent classes of quantum networks with realistic technologies; qubit amplitude damping networks and bosonic thermal-loss networks.

Submitted to QST on 1/4/22, Published 12/7/22. REVTeX, 19 pages, 3 figures

References in corpus (11)

• The Quantum Internet
• Distillation of secret key and entanglement from quantum states
• Direct and Reverse Secret-Key Capacities of a Quantum Channel
• Limits and Security of Free-Space Quantum Communications
• Satellite Quantum Communications: Fundamental Bounds and Practical Security
• The Structure of Bipartite Quantum States - Insights from Group Theory and Cryptography
• Tools for quantum network design
• Quantum communication capacity transition of complex quantum networks
• Analytical Methods for High-Rate Global Quantum Networks
• Rate limits in quantum networks with lossy repeaters
• Quantum Internet under random breakdowns and intentional attacks

Cited by in corpus (4)

• ReQuSim: Faithfully simulating near-term quantum repeaters
• On the Bipartite Entanglement Capacity of Quantum Networks
• Optimal quantum key distribution networks: capacitance versus security
• Practical Routing and Criticality in Large-Scale Quantum Communication Networks