Quantum networking with a parabolic mirror based network node

Quantum networking underpins a range of quantum-enhanced applications, including scalable quantum computing, distributed quantum sensing, and secure data communication. Although the field has advanced rapidly, efficient single-photon collection from quantum emitters and node architectures that scale to large-area quantum networks remain major challenges.

In this work, we present a compact, plug-and-play, cavity-free networking node designed to address these challenges. Our node employs an integrated on-chip architecture, in which most optical components are pre-aligned and glued in vacuum with fiber interfaces. It is based on a parabolic-mirror design that leverages approximate time-reversal symmetry between dipole trapping and photon collection, bringing performance close to the free-space collection limit [1]. This geometry provides intrinsic mode matching into a single-mode fiber while remaining robust against small misalignment and long-term drift. Using this node, we demonstrated high-quality atom–photon entanglement with a fidelity of 93% (98% after correction), which is one of the highest reported for neutral atoms. We also achieved a single-photon collection efficiency of 6.6%, roughly an order-of-magnitude improvement over previous free-space neutral-atom experiments.