Building a Hierarchical Architecture and Communication Model for the Quantum Internet

TL;DR

The paper tackles the lack of a standard quantum Internet architecture by identifying critical drawbacks of distributed designs—high maintenance costs, suboptimal entanglement distribution, and poor routing control. It proposes a three-layer hierarchical architecture with a central controller and local domain controllers to unify control and decouple entanglement preparation from the infrastructure layer, complemented by a W-state Based CEPD and a Centralized Entanglement Routing (CER) algorithm. A full-stack communication model is developed, with state-tracking (CSM/LSM) and timeouts ($t_d$, $t_{st}$) to manage errors and retries, and a concrete evaluation via NetSquid shows up to 11.5% improvement in entanglement distribution efficiency and significantly better routing fidelity and throughput compared with distributed schemes. The results demonstrate that hierarchical design can reduce maintenance, improve distribution efficiency, and enable near-optimal routing, offering a scalable pathway toward a large-scale quantum Internet; future work includes multi-controller cooperation and integrating existing repeater technologies and purification methods.

Abstract

The research of architecture has tremendous significance in realizing quantum Internet. Although there is not yet a standard quantum Internet architecture, the distributed architecture is one of the possible solutions, which utilizes quantum repeaters or dedicated entanglement sources in a flat structure for entanglement preparation & distribution. In this paper, we analyze the distributed architecture in detail and demonstrate that it has three limitations: 1) possible high maintenance overhead, 2) possible low-performance entanglement distribution, and 3) unable to support optimal entanglement routing. We design a hierarchical quantum Internet architecture and a communication model to solve the problems above. We also present a W-state Based Centralized Entanglement Preparation & Distribution (W-state Based CEPD) scheme and a Centralized Entanglement Routing (CER) algorithm within our hierarchical architecture and perform an experimental comparison with other entanglement preparation & distribution schemes and entanglement routing algorithms within the distributed architecture. The evaluation results show that the entanglement distribution efficiency of hierarchical architecture is 11.5% higher than that of distributed architecture on average (minimum 3.3%, maximum 37.3%), and the entanglement routing performance of hierarchical architecture is much better than that of a distributed architecture according to the fidelity and throughput.

Figures (17)

• Figure 1: An example of a distributed architecture. This distributed architecture example can include users, repeaters, classical and quantum channels. It relies on infrastructure layer devices (can be but not limited to repeaters) to prepare and distribute entanglement pairs for quantum communication.
• Figure 2: Entanglement distribution in distributed architecture. (a) SenderReceiver requires direct entanglement distribution between neighbor repeaters. (b) MeetInTheMiddle requires an intermediate node for performing entanglement swapping to generate entanglement pairs between repeaters. (c) MidpointSource requires a midpoint to distribute atom-atom entanglement between repeaters.
• Figure 3: Three-layer hierarchical quantum Internet architecture. The hierarchical architecture introduces the central controller and local domain controllers to the quantum Internet. The local domain controller is responsible for centralized entanglement preparation & distribution. The central controller is responsible for network control and information collection. The edge repeater (green circle) is a medium for domain interaction.
• Figure 4: Maintenance cost of distributed and hierarchical architecture
• Figure 5: Data processing and domain overhead of hierarchical architecture