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arXiv · 2001.03934

Infinite-fold enhancement in communications capacity using pre-shared entanglement

Saikat Guha·Quntao Zhuang·Boulat Bash
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Abstract

Pre-shared entanglement can significantly boost communication rates in the regime of high thermal noise, and a low-brightness transmitter. In this regime, the ratio between the entanglement-assisted capacity and the Holevo capacity, the maximum reliable-communication rate permitted by quantum mechanics without any pre-shared entanglement as a resource, is known to scale as $\log(1/N_S)$, where $N_S \ll 1$ is the mean transmitted photon number per mode. This is especially promising in enabling a large boost to radio-frequency communications in the weak-transmit-power regime, by exploiting pre-shared optical-frequency entanglement, e.g., distributed by the quantum internet. In this paper, we propose a structured design of a quantum transmitter and receiver that leverages continuous-variable pre-shared entanglement from a downconversion source, which can harness this purported infinite-fold capacity enhancement---a problem open for over a decade. Finally, the implication of this result to the breaking of the well-known {\em square-root law} for covert communications, with pre-shared entanglement assistance, is discussed.

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Saikat Guha, Quntao Zhuang, Boulat Bash. 2020-01-12. Infinite-fold enhancement in communications capacity using pre-shared entanglement. https://doi.org/10.1109/isit44484.2020.9173940

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