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Deterministic remote entanglement using a chiral quantum interconnect

Nature Physics volume 21, pages 825–830 (2025)Cite this article

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Abstract

Quantum interconnects facilitate entanglement distribution between non-local computational nodes in a quantum network. For superconducting processors, microwave photons are a natural means to mediate this distribution. However, many existing architectures limit node connectivity and directionality. In this work, we construct a chiral quantum interconnect between two nominally identical modules in separate microwave packages. Our approach uses quantum interference to emit and absorb microwave photons on demand and in a chosen direction between these modules. We optimize our protocol using model-free reinforcement learning to maximize the absorption efficiency. By halting the emission process halfway through its duration, we generate remote entanglement between modules in the form of a four-qubit W state with approximately 62% fidelity in each direction, limited mainly by propagation loss. This quantum network architecture enables all-to-all connectivity between non-local processors for modular and extensible quantum simulation and computation.

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Fig. 1: Chiral quantum interconnect experimental setup.
Fig. 2: Chiral photon emission and absorption in the time domain.
Fig. 3: Quantum state transfer between modules via directional photons.
Fig. 4: Deterministic remote entanglement generation.

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Data availability

The data that support the findings of this study are available from the corresponding authors upon reasonable request.

Code availability

The code used for numerical simulations and data analyses is available from the corresponding authors upon reasonable request.

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Acknowledgements

This research was funded in part by the Army Research Office under award no. W911NF-23-1-0045; in part by the AWS Center for Quantum Computing; and in part under Air Force contract no. FA8702-15-D-0001. A.A. acknowledges support from the Paul & Daisy Soros Fellowships program and the Clare Boothe Luce Graduate Fellowship. B.Y. acknowledges support from the Fannie and John Hertz Foundation and the NSF Graduate Research Fellowship Program. M.H. is supported by an appointment to the Intelligence Community Postdoctoral Research Fellowship Program at MIT administered by Oak Ridge Institute for Science and Education (ORISE) through an interagency agreement between the US Department of Energy and the Office of the Director of National Intelligence (ODNI). Any opinions, findings, conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the US Air Force or the US Government.

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Author notes

  1. Bharath Kannan

    Present address: Atlantic Quantum, Cambridge, MA, USA

  2. Alex Greene

    Present address: Google Quantum AI, Goleta, CA, USA

Authors and Affiliations

  1. Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA

    Aziza Almanakly, Beatriz Yankelevich, Max Hays, Bharath Kannan, Réouven Assouly, Alex Greene, Kyle Serniak, Joel Î-j. Wang, Terry P. Orlando, Simon Gustavsson, Jeffrey A. Grover & William D. Oliver

  2. Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA, USA

    Aziza Almanakly, Beatriz Yankelevich, Bharath Kannan, Alex Greene, Terry P. Orlando & William D. Oliver

  3. Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, MA, USA

    Michael Gingras, Bethany M. Niedzielski, Hannah Stickler, Mollie E. Schwartz & Kyle Serniak

  4. Department of Physics, Massachusetts Institute of Technology, Cambridge, MA, USA

    William D. Oliver

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Contributions

A.A. designed the experimental procedure and conducted the measurements. A.A. and B.Y. designed the devices, performed the theoretical calculations and simulations, analysed the data and wrote the manuscript. M.H. assisted in implementing the RL optimization. R.A. helped troubleshoot the experiments and analyse the data. A.G. assisted with the automation of calibration. M.G., B.M.N. and H.S. fabricated the devices with coordination from K.S. and M.E.S. B.Y., B.K., R.A. and J.Î.-j.W. assisted with the experimental setup. T.P.O., S.G., M.H., J.A.G. and W.D.O. supervised the project. All authors discussed the results and commented on the manuscript.

Corresponding authors

Correspondence to Aziza Almanakly or William D. Oliver.

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Nature Physics thanks Matt LaHaye and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

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Supplementary Sections A–H, Figs. 1–5, Tables 1–6 and discussion.

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Almanakly, A., Yankelevich, B., Hays, M. et al. Deterministic remote entanglement using a chiral quantum interconnect. Nat. Phys. 21, 825–830 (2025). https://doi.org/10.1038/s41567-025-02811-1

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