Comparison of techniques for distillation of entanglement over a lossy channel

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 halfway 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.