Reliable Simulation of Quantum Channels: the Error Exponent

Fuente: arXiv
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Auteurs principaux: Li, Ke, Yao, Yongsheng
Format: Preprint
Publié: 2021
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author Li, Ke
Yao, Yongsheng
author_facet Li, Ke
Yao, Yongsheng
contents The Quantum Reverse Shannon Theorem has been a milestone in quantum information theory. It states that asymptotically reliable simulation of a quantum channel, assisted by unlimited shared entanglement, requires a rate of classical communication equal to the channel's entanglement-assisted classical capacity. In this paper, we study the error exponent of quantum channel simulation, which characterizes the optimal speed of exponential convergence of the performance towards the perfect, as the blocklength increases. Based on channel purified distance, we derive lower and upper bounds for the error exponent. Then we show that the two bounds coincide when the classical communication rate is below a critical value, and hence, we have determined the exact formula of the error exponent in the low-rate case. This enables us to obtain an operational interpretation to the channel's sandwiched Rényi information of order from 1 to 2, since our formula is expressed as a transform of this quantity. In the derivation, we have also obtained an achievability bound for quantum channel simulation in the finite-blocklength setting, which is of realistic significance.
format Preprint
id arxiv_https___arxiv_org_abs_2112_04475
institution arXiv
publishDate 2021
record_format arxiv
spellingShingle Reliable Simulation of Quantum Channels: the Error Exponent
Li, Ke
Yao, Yongsheng
Quantum Physics
Information Theory
Mathematical Physics
The Quantum Reverse Shannon Theorem has been a milestone in quantum information theory. It states that asymptotically reliable simulation of a quantum channel, assisted by unlimited shared entanglement, requires a rate of classical communication equal to the channel's entanglement-assisted classical capacity. In this paper, we study the error exponent of quantum channel simulation, which characterizes the optimal speed of exponential convergence of the performance towards the perfect, as the blocklength increases. Based on channel purified distance, we derive lower and upper bounds for the error exponent. Then we show that the two bounds coincide when the classical communication rate is below a critical value, and hence, we have determined the exact formula of the error exponent in the low-rate case. This enables us to obtain an operational interpretation to the channel's sandwiched Rényi information of order from 1 to 2, since our formula is expressed as a transform of this quantity. In the derivation, we have also obtained an achievability bound for quantum channel simulation in the finite-blocklength setting, which is of realistic significance.
title Reliable Simulation of Quantum Channels: the Error Exponent
topic Quantum Physics
Information Theory
Mathematical Physics
url https://arxiv.org/abs/2112.04475