Fundamental Limit on the Power of Entanglement Assistance in Quantum Communication

Abstract

The optimal rate of reliable communication over a quantum channel can be enhanced by pre-shared entanglement. Whereas the enhancement may be unbounded in infinite-dimensional settings even when the input power is constrained, a long-standing conjecture asserts that the ratio between the entanglement-assisted and unassisted classical capacities is bounded in finite-dimensional settings [Bennett et al., IEEE Trans. Inf. Theory 48, 2637 (2002)]. In this work, we prove this conjecture by showing that their ratio is upper bounded by $o(d^2)$, where $d$ is the input dimension of the channel. An application to quantum communication with noisy encoders and decoders is given.

7 pages, 1 figure

References in corpus (4)

• Entanglement-Assisted Communication Surpassing the Ultimate Classical Capacity
• Complete entropic inequalities for quantum Markov chains
• Fault-tolerant Coding for Quantum Communication
• Fault-tolerant Coding for Entanglement-Assisted Communication

Cited by in corpus (3)

• Detecting genuine multipartite entanglement using moments of positive maps
• Reverse-type Data Processing Inequality
• Detection of nonabsolute separability in quantum states and channels through moments