Capacities of repeater-assisted quantum communications

Abstract

We consider quantum and private communications assisted by repeaters, from the basic scenario of a single repeater chain to the general case of an arbitrarily-complex quantum network, where systems may be routed through single or multiple paths. In this context, we investigate the ultimate rates at which two end-parties may transmit quantum information, distribute entanglement, or generate secret keys. These end-to-end capacities are defined by optimizing over the most general adaptive protocols that are allowed by quantum mechanics. Combining techniques from quantum information and classical network theory, we derive single-letter upper bounds for the end-to-end capacities in repeater chains and quantum networks connected by arbitrary quantum channels, establishing exact formulas under basic decoherence models, including bosonic lossy channels, quantum-limited amplifiers, dephasing and erasure channels. For the converse part, we adopt a teleportation-inspired simulation of a quantum network which leads to upper bounds in terms of the relative entropy of entanglement. For the lower bounds we combine point-to-point quantum protocols with classical network algorithms. Depending on the type of routing (single or multiple), optimal strategies corresponds to finding the widest path or the maximum flow in the quantum network. Our theory can also be extended to simultaneous quantum communication between multiple senders and receivers.

Results largely improved. Now includes the simulation and stretching of quantum networks connected by arbitrary quantum channels. The end-to-end capacities for quantum and private communication cannot beat a single-letter bound in terms of the relative entropy of entanglement

References in corpus (11)

• The Quantum Internet
• Quantum Repeaters with Photon Pair Sources and Multi-Mode Memories
• Experimental demonstration of a BDCZ quantum repeater node
• Quantum cryptography without detector vulnerabilities using optically-seeded lasers
• Direct and Reverse Secret-Key Capacities of a Quantum Channel
• Asymptotic teleportation scheme as a universal programmable quantum processor
• Rate-distance tradeoff and resource costs for all-optical quantum repeaters
• Relating quantum privacy and quantum coherence: an operational approach
• Topological optimization of quantum key distribution networks
• Repeat-until-success quantum repeaters
• Continuous Variable Quantum Repeaters

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