Realistic quantum network simulation for experimental BBM92 key distribution

TL;DR

This paper demonstrates that a discrete event quantum network simulator can accurately model BBM92 quantum key distribution, matching experimental results and theoretical predictions, thus aiding in quantum network design and optimization.

Contribution

The paper introduces a versatile discrete event quantum network simulator that accurately simulates BBM92 QKD, bridging the gap between experiments and theory in quantum network research.

Findings

Simulator matches experimental key and error rates with lower mean squared error than analytical models.

Simulator accurately predicts secure key rates in scenarios without experimental data.

Simulation aligns with theoretical predictions in untested quantum network configurations.

Abstract

Quantum key distribution (QKD) can provide secure key material between two parties without relying on assumptions about the computational power of an eavesdropper. QKD is performed over quantum links and quantum networks, systems which are resource-intensive to deploy and maintain. To evaluate and optimize performance prior to, during, and after deployment, accurate simulations with attention to physical realism are necessary. Quantum network simulators can simulate a variety of quantum and classical protocols and can assist in quantum network design and optimization by offering realism and flexibility beyond mathematical models which rely on simplifying assumptions and can be intractable to solve as network complexity increases. We use a versatile discrete event quantum network simulator to simulate the entanglement-based QKD protocol BBM92 and compare it to our experimental implementation and to existing theory. We find the discrete event quantum network simulator can match experimental key rates and error rates with a lower mean squared error than analytical theory. Furthermore, we simulate secure key rates in a repeater key distribution scenario for which no experimental implementations exist and find agreement between simulation and analytical theory. Hence, we demonstrate discrete event simulators can meet needs in quantum network simulations which cannot be filled solely by experiment or theory: discrete event simulators can accurately simulate QKD protocols and match experiments in regimes where theoretical models may require more simplifying assumptions, and they can match theoretical models in the opposite scenario where experiments have not yet been performed but theoretical models exist.