Entanglement Generation via Non-Gaussian Transfer over Atmospheric Fading Channels

TL;DR

This paper investigates the effectiveness of non-Gaussian entangled states for quantum communication over atmospheric channels, finding that Gaussian states generally outperform non-Gaussian states in realistic operational scenarios.

Contribution

It provides a comparative analysis of non-Gaussian versus Gaussian entangled states for atmospheric quantum communication, highlighting the practical advantages of Gaussian states.

Findings

Non-Gaussian states can enhance entanglement transfer under ideal conditions.

Operational scenarios favor Gaussian states due to higher entanglement-generation rates.

Implications for quantum key distribution in low-earth orbit are discussed.

Abstract

In this work we probe the usefulness of non-Gaussian entangled states as a resource for quantum communication through atmospheric channels. We outline the initial conditions in which non-Gaussian state transfer leads to enhanced entanglement transfer relative to that obtainable via Gaussian state transfer. However, we conclude that in (anticipated) operational scenarios - where most of the non-Gaussian states to be transferred over the air are created just-in-time via photonic subtraction, addition or replacement from incoming Gaussian states - the entanglement-generation rate between stations via non-Gaussian state transfer will be substantially less than that created by direct Gaussian state transfer. The role of post-selection, distillation and quantum memory in altering this conclusion is discussed, and comparison with entanglement rates produced via single-photon technologies is provided. Our results suggest that in the near term entangled Gaussian states, squeezed beyond some modest level, offer the most attractive proposition for the distribution of entanglement through high-loss atmospheric channels. The implications of our results for entanglement-based QKD to low-earth orbit are presented.