Long-distance continuous-variable quantum key distribution with quantum scissors

TL;DR

This paper explores the application of quantum scissors as non-deterministic amplifiers in continuous-variable quantum key distribution, demonstrating potential for longer-distance secure communication despite excess noise.

Contribution

It provides an exact analytical model for quantum scissors in CV-QKD and shows they can extend communication distances under certain noise conditions.

Findings

Quantum scissors can extend QKD distances with excess noise

Non-Gaussian channels are introduced by quantum scissors

Potential for quantum repeaters in CV-QKD

Abstract

The use of quantum scissors, as candidates for non-deterministic amplifiers, in continuous-variable quantum key distribution systems is investigated. Such devices rely on single-photon sources for their operation and as such, they do not necessarily preserve the Guassianity of the channel. Using exact analytical modeling for system components, we bound the secret key generation rate for the system that uses quantum scissors. We find that for non-zero values of excess noise such a system can reach longer distances than the system with no amplification. The prospect of using quantum scissors in continuous-variable quantum repeaters is therefore emboldened.