A Three-Mode Erasure Code for Continuous Variable Quantum Communications

TL;DR

This paper introduces a novel three-mode erasure code for continuous variable quantum states, significantly improving error correction in free-space quantum communication channels by nearly reversing erasures and enhancing fidelity.

Contribution

It presents the simplest known three-mode erasure code for single-mode CV states, utilizing bipartite entangled states, including non-Gaussian variants, to improve quantum communication robustness.

Findings

Almost completely reverses a single erasure

Improves fidelity for two erasures

Works with Gaussian and non-Gaussian entangled states

Abstract

Quantum states of light being transmitted via realistic free-space channels often suffer erasure errors due to several factors such as coupling inefficiencies between transmitter and receiver. In this work, an error correction code capable of protecting a single-mode quantum state against erasures is presented. Our three-mode code protects a single-mode Continuous Variable (CV) state via a bipartite CV entangled state. In realistic deployments, it can almost completely reverse a single erasure on the encoded state, and for two erasures can it improve the fidelities of received states relative to direct transmission. The bipartite entangled state used in the encoding can be Gaussian or non-Gaussian, with the latter further enhancing the performance of the code. Our new code is the simplest code known that protects a single mode against erasures and should prove useful in the construction of practical CV quantum networks that rely on free-space optics.