Clock Synchronization for Drone-Based Entanglement Quantum Key Distribution

TL;DR

This paper introduces a drone-compatible clock synchronization protocol using GNSS and entanglement-based timing correction, achieving 24 ps RMS accuracy, crucial for high-fidelity quantum key distribution in dynamic environments.

Contribution

It presents a novel synchronization method suitable for drone-based quantum networks, overcoming SWaP constraints and enabling reliable entanglement distribution.

Findings

Achieved 24 ps RMS synchronization accuracy in simulated free-space channels.

Demonstrated the protocol's effectiveness without requiring a precision reference clock.

Enabled stable entanglement distribution over dynamic distances.

Abstract

Drone-based entanglement distribution provides full spatiotemporal coverage for quantum networks, enabling quantum key distribution (QKD) in dynamic environments. The security of QKD fundamentally depends on high-fidelity quantum state measurements, for which high-precision clock synchronization is indispensable, as timing jitter is inversely correlated with quantum state fidelity. However, drone-based clock synchronization is constrained by SWaP (Size, Weight, and Power) limitations and dynamic mobility effects. Here, we propose a synchronization protocol for drone-based entanglement distribution, leveraging nanosecond-accurate Global Navigation Satellite System (GNSS) timing and entanglement-based timing correction to overcome SWaP constraints. Experimental results demonstrate 24 ps RMS synchronization in simulated free-space quantum channels with distance dynamics, without requiring precision reference clock. Our protocol enables drone-based entanglement distribution, paving the way for seamless wide-area and local-area quantum internet.