Local Gaussian operations can enhance continuous-variable entanglement distillation

TL;DR

This paper demonstrates that local Gaussian operations, specifically squeezing, can improve the performance and efficiency of non-Gaussian entanglement distillation protocols in quantum communication.

Contribution

It shows that local Gaussian unitaries, such as squeezing, can enhance existing entanglement distillation schemes, even with lossy channel conditions.

Findings

Local squeezing improves distillation performance.

Optimal Gaussian unitaries can be derived for enhancement.

Enhancement is effective in realistic lossy channels.

Abstract

Entanglement distillation is a fundamental building block in long-distance quantum communication. Though known to be useless on their own for distilling Gaussian entangled states, local Gaussian operations may still help to improve non-Gaussian entanglement distillation schemes. Here we show that by applying local squeezing operations, both the performance and the efficiency of existing distillation protocols can be enhanced. We derive the optimal enhancement through local Gaussian unitaries, which can be obtained even in the most natural scenario when Gaussian mixed entangled states are shared after their distribution through a lossy-fiber communication channel.