Quantum networks (QNs) enable qubit transfer between distant nodes through quantum teleportation, which reconstructs a quantum state at a remote node by consuming a shared Bell pair. In multi-qubit quantum applications (QApps), the teleported qubits may need to remain stored in quantum memories until execution can start, while decoherence progressively reduces their fidelity with respect to the ideal target state. Such QApps can operate only if all teleported qubits simultaneously satisfy a minimum fidelity threshold. In this paper, we study how many qubits can be teleported under this fidelity-constrained operation in a two-node QN. To this end, we define a QApp-level reliability metric as the probability that all end-to-end Bell pairs satisfy the target fidelity when the multi-qubit teleportation stage is completed. We then develop a Monte Carlo simulator that captures stochastic Bell-pair generation, Quantum Repeater (QR)-assisted entanglement distribution, and fidelity degradation. The analysis considers fiber-based and terrestrial free-space optical (FSO) quantum links, as well as representative NV-center- and trapped-ion-based quantum memories. Results show that memory coherence is the main scalability bottleneck under stringent fidelity targets, while parallel entanglement generation is essential for multi-qubit teleportation.

翻译：量子网络（QN）通过量子隐形传态实现远距离节点间的量子比特转移，该过程通过消耗共享的贝尔对在远程节点重构量子态。在多量子比特量子应用（QApp）中，传送的量子比特可能需要存储在量子存储器中直至执行开始，而退相干会逐步降低其相对于理想目标态的保真度。此类QApp仅在所有传送的量子比特同时满足最小保真度阈值时才能运行。本文研究了在双节点QN中，受此保真度约束操作下可传送的量子比特数量。为此，我们定义了一个QApp层面的可靠性度量指标，该指标衡量多量子比特传送阶段完成时，所有端到端贝尔对满足目标保真度的概率。随后我们开发了蒙特卡洛模拟器，该模拟器捕获了随机贝尔对生成、量子中继器（QR）辅助纠缠分发以及保真度退化过程。分析考虑了基于光纤和地面自由空间光（FSO）的量子链路，以及代表性的NV色心型和离子阱型量子存储器。结果表明，在严苛的保真度目标下，存储器相干性是可扩展性的主要瓶颈，而并行纠缠生成对多量子比特传送至关重要。