Simulation of entanglement based quantum networks for performance characterization
David Pérez Castro, Juan Fernández-Herrerín, Ana Fernández-Vilas, Manuel Fernández-Veigaa, Rebeca P. Díaz-Redondo
TL;DR
The paper addresses the challenge of characterizing entanglement-based quantum networks (EBNs) by extending NetSquid with a fidelity-aware routing framework and a general topology model $G=(V,E,\{\,\omega_e\}\!)$ where edge weights correspond to entanglement fidelity. A network hypervisor preassigns end-to-end paths and orchestrates swapping, purification, and correction protocols to maximize end-to-end fidelity $F$ while respecting delays $\ell$ and persistence $\delta$, enabling end-to-end teleportation applications. The authors perform a comprehensive set of simulations to quantify how memory technologies (e.g., SiV vs NV), gate durations, and the number of intermediate nodes affect fidelity $F$, capacity $C$, and processing overhead $T$, revealing key tradeoffs and design guidelines for scalable EBNs. They find that memory storage time $T_1$ and channel losses dominate performance, SiV memories offer higher entanglement rates up to about $40$ km, and purification versus error-correction strategies exhibit distance-dependent gains, with purification advantageous up to around $70$ km under certain noise models. The work provides a practical, extensible tool for engineering quantum networks and informs decisions on topology, memory technology, and protocol choices for near- to mid-term quantum communication deployments.
Abstract
Entanglement-based networks (EBNs) enable general-purpose quantum communication by combining entanglement and its swapping in a sequence that addresses the challenges of achieving long distance communication with high fidelity associated with quantum technologies. In this context, entanglement distribution refers to the process by which two nodes in a quantum network share an entangled state, serving as a fundamental resource for communication. In this paper, we study the performance of entanglement distribution mechanisms over a physical topology comprising end nodes and quantum switches, which are crucial for constructing large-scale links. To this end, we implemented a switch-based topology in NetSquid and conducted a series of simulation experiments to gain insight into practical and realistic quantum network engineering challenges. These challenges include, on the one hand, aspects related to quantum technology, such as memory technology, gate durations, and noise; and, on the other hand, factors associated with the distribution process, such as the number of switches, distances, purification, and error correction. All these factors significantly impact the end-to-end fidelity across a path, which supports communication between two quantum nodes. We use these experiments to derive some guidelines towards the design and configuration of future EBNs.