Multi-channel microwave and optical control of quantum memories fabricated in parallel from diamond membranes on functionalized substrates

Diamond color centers have been deployed to enable a variety of state-of-the-art quantum networking demonstrations [1] that promise to enable distributed quantum sensing, blind quantum computing, distributed quantum computing, and long distance communication technologies. However, deployment of these technologies is limited by the challenge of  developing wafer-scale manufacturing of diamond photonic devices of sufficient quality to host performant quantum memories. One of the factors determining the quantum network performance is the total number of parallel memory channels [2]. Here [3] we demonstrate a major advancement towards large-scale production of quantum memories on diamond thin films with a deterministic, highly efficient optical interface, and heterogeneous integration to substrates functionalized with electronic control lines such as buried coplanar waveguides (bCPWs) for microwave delivery and parallel microwave-driving of several devices reducing the thermal budget of such quantum platform. Photonic crystal cavities (PhCs) are patterned on a diamond thin film containing silicon vacancy centers ensuring high fidelity and reliability spin-photon interactions [3, 4]. This technology paves the way for large scale, foundry style production of integrated diamond photonic devices.

[1] Katsumi, Ryota, et al. "Recent progress in hybrid diamond photonics for quantum information processing and sensing." Communications Engineering 4.1 (2025): 85; Ding, Sophie W., et al. "High-Q cavity interface for color centers in thin film diamond." nature communications 15.1 (2024): 6358.

[2] Ruskuc, A. et al. Multiplexed entanglement of multi-emitter quantum network nodes. Nature 639, 54–59 (2025).

[3] Riedel, Daniel, et al. "A scalable photonic quantum interconnect platform." arXiv preprint arXiv:2508.06675 (2025).

[4] Meesala, Srujan, et al. "Strain engineering of the silicon-vacancy center in diamond." Physical Review B 97.20 (2018): 205444.