Comparison of Techniques for Distillation of Entanglement over a Lossy Channel

TL;DR

This paper compares three quantum entanglement distillation protocols over lossy channels, evaluating their effectiveness with realistic imperfections, and finds that a distributed NLA protocol generally outperforms others except in specific ideal conditions.

Contribution

It provides a comparative analysis of quantum entanglement distillation techniques considering practical imperfections, highlighting the advantages of a distributed NLA protocol.

Findings

Distributed NLA outperforms other protocols in most scenarios.

Performance depends on channel distance and source quality.

Distributed NLA is advantageous except at very short distances or with high-quality sources.

Abstract

We analyze three quantum communication protocols that have been proposed in the literature, and compare how well they communicate single-rail entanglement. We use specific metrics for output state purity and probability of success and include the presence of imperfect photon source and detection components. We find that a distributed noiseless linear amplification (NLA) protocol with a relay point placed half-way between Alice and Bob outperforms NLA at Bob's end and a recently proposed purification protocol under most conditions, unless the distance is very small or the photon source component is very good.