Continuous-variable measurement-device-independent quantum key distribution with photon subtraction

TL;DR

This paper demonstrates that applying photon subtraction, a non-Gaussian operation, to continuous-variable measurement-device-independent quantum key distribution enhances its security and transmission distance, making experimental implementation more feasible.

Contribution

It introduces a photon subtraction method to improve CV-MDI-QKD, extending its transmission range and practicality compared to previous protocols.

Findings

Photon subtraction increases maximal transmission distance.

1-photon subtraction yields optimal performance.

The method is compatible with existing technologies.

Abstract

It has been found that non-Gaussian operations can be applied to increase and distill entanglement between Gaussian entangled states. We show the successful use of the non-Gaussian operation, in particular, photon subtraction operation, on the continuous-variable measurement-device-independent quantum key distribution (CV-MDI-QKD) protocol. The proposed method can be implemented based on existing technologies. Security analysis shows that the photon subtraction operation can remarkably increase the maximal transmission distance of the CV-MDI-QKD protocol, which precisely make up for the shortcoming of the original CV-MDI-QKD protocol, and 1-photon subtraction operation has the best performance. Moreover, the proposed protocol provides a feasible method for the experimental implementation of the CV-MDI-QKD protocol.