IDEAS home Printed from https://ideas.repec.org/a/nat/nature/v607y2022i7920d10.1038_s41586-022-04891-y.html
   My bibliography  Save this article

A device-independent quantum key distribution system for distant users

Author

Listed:
  • Wei Zhang

    (Ludwig-Maximilians-Universität
    Munich Center for Quantum Science and Technology (MCQST))

  • Tim Leent

    (Ludwig-Maximilians-Universität
    Munich Center for Quantum Science and Technology (MCQST))

  • Kai Redeker

    (Ludwig-Maximilians-Universität
    Munich Center for Quantum Science and Technology (MCQST))

  • Robert Garthoff

    (Ludwig-Maximilians-Universität
    Munich Center for Quantum Science and Technology (MCQST))

  • René Schwonnek

    (Universität Siegen
    National University of Singapore)

  • Florian Fertig

    (Ludwig-Maximilians-Universität
    Munich Center for Quantum Science and Technology (MCQST))

  • Sebastian Eppelt

    (Ludwig-Maximilians-Universität
    Munich Center for Quantum Science and Technology (MCQST))

  • Wenjamin Rosenfeld

    (Ludwig-Maximilians-Universität
    Munich Center for Quantum Science and Technology (MCQST))

  • Valerio Scarani

    (National University of Singapore
    National University of Singapore)

  • Charles C.-W. Lim

    (National University of Singapore
    National University of Singapore
    JPMorgan Chase)

  • Harald Weinfurter

    (Ludwig-Maximilians-Universität
    Munich Center for Quantum Science and Technology (MCQST)
    Max-Planck Institut für Quantenoptik)

Abstract

Device-independent quantum key distribution (DIQKD) enables the generation of secret keys over an untrusted channel using uncharacterized and potentially untrusted devices1–9. The proper and secure functioning of the devices can be certified by a statistical test using a Bell inequality10–12. This test originates from the foundations of quantum physics and also ensures robustness against implementation loopholes13, thereby leaving only the integrity of the users’ locations to be guaranteed by other means. The realization of DIQKD, however, is extremely challenging—mainly because it is difficult to establish high-quality entangled states between two remote locations with high detection efficiency. Here we present an experimental system that enables for DIQKD between two distant users. The experiment is based on the generation and analysis of event-ready entanglement between two independently trapped single rubidium atoms located in buildings 400 metre apart14. By achieving an entanglement fidelity of $$ {\mathcal F} \,\ge 0.892(23)$$ ℱ ≥ 0.892 ( 23 ) and implementing a DIQKD protocol with random key basis15, we observe a significant violation of a Bell inequality of S = 2.578(75)—above the classical limit of 2—and a quantum bit error rate of only 0.078(9). For the protocol, this results in a secret key rate of 0.07 bits per entanglement generation event in the asymptotic limit, and thus demonstrates the system’s capability to generate secret keys. Our results of secure key exchange with potentially untrusted devices pave the way to the ultimate form of quantum secure communications in future quantum networks.

Suggested Citation

  • Wei Zhang & Tim Leent & Kai Redeker & Robert Garthoff & René Schwonnek & Florian Fertig & Sebastian Eppelt & Wenjamin Rosenfeld & Valerio Scarani & Charles C.-W. Lim & Harald Weinfurter, 2022. "A device-independent quantum key distribution system for distant users," Nature, Nature, vol. 607(7920), pages 687-691, July.
  • Handle: RePEc:nat:nature:v:607:y:2022:i:7920:d:10.1038_s41586-022-04891-y
    DOI: 10.1038/s41586-022-04891-y
    as

    Download full text from publisher

    File URL: https://www.nature.com/articles/s41586-022-04891-y
    File Function: Abstract
    Download Restriction: Access to the full text of the articles in this series is restricted.

    File URL: https://libkey.io/10.1038/s41586-022-04891-y?utm_source=ideas
    LibKey link: if access is restricted and if your library uses this service, LibKey will redirect you to where you can use your library subscription to access this item
    ---><---

    As the access to this document is restricted, you may want to search for a different version of it.

    Citations

    Citations are extracted by the CitEc Project, subscribe to its RSS feed for this item.
    as


    Cited by:

    1. Jie Zhao & Hao Jeng & Lorcán O. Conlon & Spyros Tserkis & Biveen Shajilal & Kui Liu & Timothy C. Ralph & Syed M. Assad & Ping Koy Lam, 2023. "Enhancing quantum teleportation efficacy with noiseless linear amplification," Nature Communications, Nature, vol. 14(1), pages 1-8, December.
    2. Peter Schiansky & Julia Kalb & Esther Sztatecsny & Marie-Christine Roehsner & Tobias Guggemos & Alessandro Trenti & Mathieu Bozzio & Philip Walther, 2023. "Demonstration of quantum-digital payments," Nature Communications, Nature, vol. 14(1), pages 1-7, December.

    More about this item

    Statistics

    Access and download statistics

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:nat:nature:v:607:y:2022:i:7920:d:10.1038_s41586-022-04891-y. See general information about how to correct material in RePEc.

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    We have no bibliographic references for this item. You can help adding them by using this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: Sonal Shukla or Springer Nature Abstracting and Indexing (email available below). General contact details of provider: http://www.nature.com .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.