Sending or not sending: twin-field quantum key distribution with large misalignment error

TL;DR

This paper introduces a fault-tolerant twin-field quantum key distribution protocol that achieves secure communication over distances exceeding 700 km despite high misalignment errors, leveraging a novel TF-QKD concept.

Contribution

It proposes a new sending-or-not-sending TF-QKD protocol that maintains security over long distances with high misalignment errors, advancing quantum communication technology.

Findings

Secure distance exceeds 700 km with 15% misalignment error

Protocol surpasses 800 km secure distance with zero misalignment

Demonstrates robustness of TF-QKD under practical error conditions

Abstract

Based on the novel idea of twin-field quantum key distribution, we present a sending-or-not-sending twin-field fault tolerant quantum key distribution protocol. Our protocol can access a secure distance longer than 700 km even though the misalignment error rate is $15\%$. In the case of zero alignment error, our protocol can exceeds a secure distance of 800 km. Thanks to the novel idea of TF-QKD !