Quantum repeater networks require independent absorptive quantum memories capable of storing and retrieving indistinguishable photons to perform high-repetition entanglement swapping operations. The ability to perform these coherent operations at room temperature is of prime importance for the realization of scalable quantum networks. We perform Hong-Ou-Mandel (HOM) interference between photonic polarization states and single-photon-level pulses stored and retrieved from two sets of independent room-temperature quantum memories. We show that the storage and retrieval of polarization states from quantum memories does not degrade the HOM visibility for few-photon-level polarization states in a dual-rail configuration. For single-photon-level pulses, we measure the HOM visibility with various levels of background in a single polarization, single-rail QM, and investigate its dependence on the signal-to-background ratio. We obtain an HOM visibility of 43%, compared to the 48% no-memory limit of our set-up. These results allow us to estimate a 33% visibility for polarization qubits under the same conditions. These demonstrations lay the groundwork for future applications using large-scale memory-assisted quantum networks.

量子中继器网络需要独立的吸收性量子存储器，能够存储和检索不可区分的光子，以执行高重复纠缠交换操作。在室温下执行这些相干操作的能力对于实现可扩展的量子网络至关重要。我们在光子偏振态和从两组独立的室温量子存储器中存储和检索的单光子级脉冲之间进行红欧曼德尔（HOM）干涉。我们证明，从量子存储器存储和检索偏振态不会降低双轨配置中少光子级偏振态的 HOM 可见性。对于单光子级脉冲，我们在单偏振、单轨 QM 中测量不同背景水平的 HOM 可见度，并研究其对信号背景比的依赖性。我们获得的 HOM 可见性为 43%，而我们的设置的无内存限制为 48%。这些结果使我们能够估计相同条件下偏振量子位的可见度为 33%。这些演示为未来使用大规模内存辅助量子网络的应用奠定了基础。