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Entangling atomic spins with a Rydberg-dressed spin-flip blockade

Nature Physics volume 12, pages 7174 (2016) | Download Citation

Abstract

Controlling the quantum entanglement between parts of a many-body system is key to unlocking the power of quantum technologies such as quantum computation, high-precision sensing, and the simulation of many-body physics. The spin degrees of freedom of ultracold neutral atoms in their ground electronic state provide a natural platform for such applications thanks to their long coherence times and the ability to control them with magneto-optical fields. However, the creation of strong coherent coupling between spins has been challenging. Here we demonstrate a strong and tunable Rydberg-dressed interaction between spins of individually trapped caesium atoms with energy shifts of order 1 MHz in units of Planck’s constant. This interaction leads to a ground-state spin-flip blockade, whereby simultaneous hyperfine spin flips of two atoms are inhibited owing to their mutual interaction. We employ this spin-flip blockade to rapidly produce single-step Bell-state entanglement between two atoms with a fidelity ≥81(2)%.

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Acknowledgements

We would like to thank L. P. Parazzoli and C. W. Chou for their early work on the experimental system. We also thank J. Lee for comments on the manuscript. This work was supported by the Laboratory Directed Research and Development programme at Sandia National Laboratories and through the National Science Foundation’s Center for Quantum Information and Control NSF-1212445.

Author information

Affiliations

  1. Sandia National Laboratories, Albuquerque, New Mexico 87123, USA

    • Y.-Y. Jau
    • , A. M. Hankin
    • , T. Keating
    • , I. H. Deutsch
    •  & G. W. Biedermann
  2. Center for Quantum Information and Control (CQuIC), University of New Mexico, Albuquerque, New Mexico 87131, USA

    • Y.-Y. Jau
    • , A. M. Hankin
    • , T. Keating
    • , I. H. Deutsch
    •  & G. W. Biedermann

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Contributions

Experimental work by Y.-Y.J., A.M.H. and G.W.B. Numerical modelling by Y.-Y.J. Theoretical work by I.H.D. and T.K.

Competing interests

The authors declare no competing financial interests.

Corresponding author

Correspondence to G. W. Biedermann.

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DOI

https://doi.org/10.1038/nphys3487

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