Teleportation improvement by non-deterministic noiseless linear amplification

TL;DR

This paper explores how non-deterministic noiseless linear amplification enhances entanglement and teleportation fidelity in continuous-variable quantum states, showing improvements in security and performance over traditional methods.

Contribution

It provides a detailed analysis of entanglement and non-Gaussian features after NL-amplification and demonstrates improved teleportation performance using these amplified states.

Findings

Entanglement always increases after NL-amplification.

Improved EPR correlations occur only with low-energy input states.

Teleportation fidelity and security can be enhanced with optimized NLA parameters.

Abstract

We address de-Gaussification of continuous variables Gaussian states by optimal non-deterministic noiseless linear amplifier (NLA) and analyze in details the properties of the amplified states. In particular, we investigate the entanglement content and the non-Gaussian character for the class of non-Gaussian entangled state obtained by using NL-amplification of two-mode squeezed vacua (twin-beam, TWB). We show that entanglement always increases, whereas improved EPR correlations are observed only when the input TWB has low energy. We then examine a Braunstein-Kimble-like protocol for the teleportation of coherent states, and compare the performances of TWB-based teleprotation with those obtained using NL-amplified resources. We show that teleportation fidelity and security may be improved for a large range of NLA parameters (gain and threshold).