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  • Open Access

Continuous Variable Measurement-Device-Independent Quantum Certification

B. L. Larsen1,*, A. A. E. Hajomer1, P. Abiuso2, S. Izumi1, T. Gehring1, J. S. Neergaard-Nielsen1, A. Acín3,4, and U. L. Andersen1,†

  • *Contact author: blula@dtu.dk
  • †Contact author: ulun@dtu.dk
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Phys. Rev. X 16, 011070 – Published 30 March, 2026

DOI: https://doi.org/10.1103/g92b-2kwg

Abstract

Secure and reliable certification of quantum resources is a fundamental challenge in the advancement of next-generation quantum technologies, particularly as devices become more complex and integrated into practical applications, where parts of the system may be untrusted or inaccessible by users. Addressing this challenge requires certification methods that rely on minimal assumptions and limited trust while still faithfully and reliably verifying the quantum resources in question. For infinite-dimensional bosonic systems, existing certification methods rely on fully trusted and well-calibrated measurement systems, leaving significant security vulnerabilities open. In this work, we present the first experimental demonstration of measurement-device-independent (MDI) certification schemes for infinite-dimensional bosonic systems, where the certification process is conducted using entirely untrusted measurement devices and assuming only the trusted preparation of coherent states. Specifically, we implement schemes for the MDI certification of continuous-variable (CV) entanglement and the operation of an elementary optical CV quantum memory. We leverage techniques of Bayesian metrology and exploit the practicality and accessibility of Gaussian quantum optics to achieve secure and efficient certification. These results demonstrate the potential of the MDI framework to enhance trust in quantum technologies with applications in quantum communication and quantum computing.

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Popular Summary

Reliably certifying quantum devices is a significant challenge when components are untrusted or inaccessible to the user. We present an experimental demonstration of measurement-device-independent certification for infinite-dimensional bosonic systems by verifying continuous-variable entanglement and an optical quantum memory. Our approach uses trusted preparations of coherent states while treating all measurement devices as entirely untrusted black boxes. We show entanglement in the form of a two-mode squeezed vacuum state and an optical memory in the form of a fiber spool. These results prove that secure certification is possible with minimal assumptions, offering a practical framework for validating complex hardware from external service providers.

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Phys. Rev. X 16, 011070– Published 30 March, 2026
  • Received 1 April 2025
  • Revised 16 October 2025
  • Accepted 9 February 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.

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