Optical links for control and readout of superconducting qubits: toward scalable, low heatload architectures

ORAL

Abstract

Superconducting qubits are a leading platform for realizing fault-tolerant quantum computers [1], yet current state-of-the-art quantum processing units (QPUs) scale still fall short by several orders of magnitude for practical applications [2]. A major bottleneck is the passive heat load of coaxial wiring and the active heat load from cryogenic amplifiers (HEMTs), which consume much of the cooling capacity of dilution refrigerators [3].

Recent works have demonstrated coherent optical control of superconducting qubits using electro-optic modulation and photodiodes in dilution refrigerators [4-5]. Additionally, microwave-to-optics transducers have been used for both optical control [6] and optical readout [7-9]. These demonstrations highlight the feasibility of all-optical I/O for superconducting qubits. However, deploying large scale optical I/O systems with equivalent performance to conventional microwave techniques remains a challenge.

In this work, we experimentally demonstrate a scalable platform for optical qubit control. Our solution consists of a photodiode array with custom cryogenic optical packaging, suitable for high-performance qubit operation. Combining with optical readout using piezo-optomechanical transducers, we further lay out an optical I/O roadmap towards tens of thousands of superconducting qubits. We evaluate the resulting heat-load advantages, highlighting their ability to overcome key scaling bottlenecks toward fault-tolerant quantum computing

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Publication: [1] Krantz, P. et al. (2019) 'A Quantum Engineer's Guide to superconducting qubits', Applied Physics Reviews, 6(2).
[2] Alexeev, Y. et al. (2021) 'Quantum Computer Systems for Scientific Discovery', PRX Quantum, 2(1).
[3] Krinner, S. et al. (2019) 'Engineering cryogenic setups for 100-qubit scale superconducting circuit systems', EPJ Quantum Technology, 6(1)
[4] Lecocq, F., Quinlan, F., Cicak, K. et al. Control and readout of a superconducting qubit using a photonic link. Nature 591, 575–579 (2021). https://doi.org/10.1038/s41586-021-03268-x
[5] Xu, W., Guo, T., Zhang, K. et al. Manipulations of a transmon qubit with a null-biased electro-optic fiber link. Nat Commun 16, 2629 (2025). https://doi.org/10.1038/s41467-025-57820-8
[6] Warner, H.K., Holzgrafe, J., Yankelevich, B. et al. Coherent control of a superconducting qubit using light. Nat. Phys. 21, 831–838 (2025). https://doi.org/10.1038/s41567-025-02812-0
[7] van Thiel, T.C., Weaver, M.J., Berto, F. et al. Optical readout of a superconducting qubit using a piezo-optomechanical transducer. Nat. Phys. 21, 401–405 (2025). https://doi.org/10.1038/s41567-024-02742-3
[8] Delaney, R.D., Urmey, M.D., Mittal, S. et al. Superconducting-qubit readout via low-backaction electro-optic transduction. Nature 606, 489–493 (2022). https://doi.org/10.1038/s41586-022-04720-2
[9] Arnold, G., Werner, T., Sahu, R. et al. All-optical superconducting qubit readout. Nat. Phys. 21, 393–400 (2025). https://doi.org/10.1038/s41567-024-02741-4

Presenters

  • Beer O de Zoeten

    • QphoX

Authors

  • Eugenio Cataldo

    • QphoX

  • Reza Hajitashakkori

    • QphoX

  • Mohammad Kobba

    • QphoX

  • Thierry C van Thiel

    • QphoX

  • Abhinand Pusuluri

    • QphoX

  • Mahnaz Zarrinfar

    • QphoX

  • Kamal Pandey

    • QphoX

  • Bennett Sprague

    • QphoX

  • Beer O de Zoeten

    • QphoX

  • Matthew J Weaver

    • QphoX
    • Qphox

  • Katie J Helsby

    • QphoX

  • Jana Bauer

    • Delft University of Technology

  • Lorenzo Scarpelli

    • Delft University of Technology

  • Robert Stockill

    • QphoX

  • Simon Gröblacher

    • QphoX