Non-Gaussian entanglement swapping

TL;DR

This paper explores non-Gaussian entanglement swapping using tunable squeezed Bell states, demonstrating that non-Gaussian resources improve teleportation fidelity under realistic loss conditions, crucial for robust quantum communication.

Contribution

It introduces a non-Gaussian entanglement swapping protocol with tunable states and shows its advantage over Gaussian states in realistic noisy environments.

Findings

Non-Gaussian resources enhance teleportation fidelity with increased squeezing.

Optimized non-Gaussian states outperform Gaussian states under losses.

Non-Gaussian entanglement swapping is essential for decoherence-resilient quantum communication.

Abstract

We investigate the continuous-variable entanglement swapping protocol in a non-Gaussian setting, with non- Gaussian states employed either as entangled inputs and/or as swapping resources. The quality of the swapping protocol is assessed in terms of the teleportation fidelity achievable when using the swapped states as shared entangled resources in a teleportation protocol. We thus introduce a two-step cascaded quantum communication scheme that includes a swapping protocol followed by a teleportation protocol. The swapping protocol is fed by a general class of tunable non-Gaussian states, the squeezed Bell states, which, by means of controllable free parameters, allows for a continuous morphing from Gaussian twin beams up to maximally non-Gaussian squeezed number states. In the realistic instance, taking into account the effects of losses and imperfections, we show that as the input two-mode squeezing increases, optimized non-Gaussian swapping resources allow for a monotonically increasing enhancement of the fidelity compared to the corresponding Gaussian setting. This result implies that the use of non-Gaussian resources is necessary to guarantee the success of continuous-variable entanglement swapping in the presence of decoherence.