A hybrid quantum network linking telecom-wavelength atomic and solid-state nodes

TL;DR

This paper demonstrates a pioneering two-node hybrid quantum network operating entirely in the telecom C-band, integrating atomic and solid-state quantum systems without frequency conversion, advancing scalable quantum communication.

Contribution

It introduces a novel telecom-band quantum network linking atomic and solid-state nodes with high performance, avoiding complex frequency conversion, and supporting long-distance, multiplexed quantum communication.

Findings

Achieved high single-photon purity at 46 kcps

Demonstrated 10.6% storage efficiency with multimode capacity

Supported non-classicality preservation over 49.2 km fiber

Abstract

Photonic links between disparate quantum technologies$-$such as photon sources, memories, processors, clocks, and sensors$-$are key to scaling quantum networks and realizing a versatile quantum internet for secure quantum communication, distributed quantum computing, and entanglement-enhanced metrology. In practice, each technology is most suitably implemented on a different quantum platform; the substantial spectral mismatch between them, along with scarce native telecom interfaces, thus poses a major bottleneck to achieving efficient interconnections over long distances. Here we demonstrate the first deployed two-node hybrid network that operates entirely in the telecom C-band. Our approach uses no quantum frequency conversion or external filtering; instead, we develop a neutral atom single photon source and a solid-state rare-earth quantum memory that both operate in previously unexplored telecom regimes with state-of-the-art performance. The source achieves a high single-photon purity at 46 kcps, and the memory a storage efficiency of 10.6% with high multimode capacity. We leverage the intrinsic tunability of both systems to optimize their spectral overlap and demonstrate microsecond-level storage and retrieval with a large time-bandwidth product. Moreover, we showcase real-world networking competencies such as support for multiplexing across 37 temporal modes and preservation of non-classicality over fibers of 10.6 km (metropolitan) and 49.2 km (laboratory). Our work establishes a backbone for telecom-native quantum repeater links and unlocks a path towards high-bandwidth, large-scale quantum networking.