Improving continuous-variable entanglement distribution by separable states

TL;DR

This paper introduces a simplified and more efficient protocol for distributing continuous-variable entanglement using a separable auxiliary mode, achieving significantly higher entanglement than previous methods.

Contribution

A new protocol is proposed that enhances entanglement distribution efficiency and simplifies the process compared to earlier approaches.

Findings

Achieves over an order of magnitude higher logarithmic negativity.

Demonstrates entanglement restoration through interference with a separable mode.

Shows entanglement originates from initial mode and auxiliary mode interactions.

Abstract

We investigate the physical mechanism behind the counterintuitive phenomenon, the distribution of continuous-variable entanglement between two distant modes by sending a third separable auxiliary mode between them. For this purpose, we propose a new more simple and more efficient protocol resulting in distributed entanglement with more than an order of the magnitude higher logarithmic negativity than in the previously proposed protocol. This new protocol shows that the distributed entanglement originates from the entanglement of one mode and the auxiliary mode used for distribution which is first destroyed by local correlated noises and restored subsequently by the interference of the auxiliary mode with the second distant separable correlated mode.