Loss-resilient photonic entanglement swapping using optical hybrid states

TL;DR

This paper introduces a loss-resilient entanglement swapping scheme using hybrid optical states, demonstrating robustness to losses and detection inefficiencies, suitable for practical quantum key distribution.

Contribution

The paper presents a novel hybrid entanglement swapping scheme that maintains high entanglement under photon losses and detection inefficiencies, advancing quantum communication.

Findings

Hybrid states with small amplitudes outperform discrete-variable entanglement under loss.

The scheme shows robustness to detection inefficiency.

Potential application in practical quantum key distribution.

Abstract

We propose a scheme of loss-resilient entanglement swapping between two distant parties via an imperfect optical channel. In this scheme, two copies of hybrid entangled states are prepared and the continuous-variable parts propagate through lossy media. In order to perform successful entanglement swapping, several different measurement schemes are considered for the continuousvariable parts such as single-photon detection for ideal cases and a homodyne detection for practical cases. We find that the entanglement swapping using hybrid states with small amplitudes offers larger entanglement than the discrete-variable entanglement swapping in the presence of large losses. Remarkably, this hybrid scheme still offers excellent robustness of entanglement to the detection inefficiency. Thus, the proposed scheme could be used for the practical quantum key distribution in hybrid optical states under photon losses.