Cut-and-paste restoration of entanglement transmission

TL;DR

This paper introduces a novel 'cut-and-paste' protocol that enhances entanglement transmission over noisy quantum channels by extracting and reshuffling sub-components, supported by theoretical analysis and a proof-of-principle quantum optics experiment.

Contribution

The work presents a new protocol for improving entanglement distribution in noisy quantum channels through component reshuffling, with experimental validation.

Findings

The protocol can improve entanglement transmission in highly noisy channels.

Experimental demonstration confirms the feasibility of the cut-and-paste method.

Theoretical analysis explains the counterintuitive correction mechanism.

Abstract

The distribution of entangled quantum systems among two or more nodes of a network is a key task at the basis of quantum communication, quantum computation and quantum cryptography. Unfortunately the transmission lines used in this procedure can introduce so much perturbations and noise in the transmitted signal that prevent the possibility of restoring quantum correlations in the received messages either by means of encoding optimization or by exploiting local operations and classical communication. In this work we present a procedure which allows one to improve the performance of some of these channels. The mechanism underpinning this result is a protocol which we dub cut-and-paste, as it consists in extracting and reshuffling the sub-components of these communication lines, which finally succeed in "correcting each other". The proof of this counterin- tuitive phenomenon, while improving our theoretical understanding of quantum entanglement, has also a direct application in the realization of quantum information networks based on imperfect and highly noisy communication lines. A quantum optics experiment, based on the transmission of single-photon polarization states, is also presented which provides a proof-of-principle test of the proposed protocol.