Towards Telecommunication-Band Quantum Networking with an Atom-Cavity Platform

Long-distance quantum networks could unlock powerful capabilities in quantum information science, including secure communication, nonlocal sensing, and distributed quantum computing. We report progress toward a telecom networking platform based on individually trapped ⁸⁷Rb atoms coupled to a high-finesse microcavity, utilizing an intrinsic telecom transition at 1530~nm. First, in free space we probe the emission cascade from 4D_5/2 →5P_3/2 → 5S_1/2 by performing cross-correlation measurements between the emitted 1530 and 780 nm photons. Our proposed entanglement scheme employs stretched-state qubits, which are optimal for fast, high-fidelity entanglement. Consequently, we demonstrate coherent Raman-based control of such states and characterize their coherence times. Finally, we image multiple transverse modes of the cavity by performing atomic pushout measurements at rasterized positions. Together, these results establish key ingredients for scalable, long-range quantum networking at telecom wavelengths. Furthermore, this enables potential integration with silicon nanophotonics for multiplexing and on-chip entanglement routing.