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Observation of Rydberg blockade between two atoms

Nature Physics volume 5, pages 110114 (2009) | Download Citation

Abstract

Blockade interactions whereby a single particle prevents the flow or excitation of other particles provide a mechanism for control of quantum states, including entanglement of two or more particles. Blockade has been observed for electrons1,2,3, photons4 and cold atoms5. Furthermore, dipolar interactions between highly excited atoms have been proposed as a mechanism for ‘Rydberg blockade’6,7, which might provide a novel approach to a number of quantum protocols8,9,10,11. Dipolar interactions between Rydberg atoms were observed several decades ago12 and have been studied recently in a many-body regime using cold atoms13,14,15,16,17,18. However, to harness Rydberg blockade for controlled quantum dynamics, it is necessary to achieve strong interactions between single pairs of atoms. Here, we demonstrate that a single Rydberg-excited rubidium atom blocks excitation of a second atom located more than 10 μm away. The observed probability of double excitation is less than 20%, consistent with a theoretical model of the Rydberg interaction augmented by Monte Carlo simulations that account for experimental imperfections.

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Acknowledgements

This work was supported by the NSF and ARO-IARPA.

Author information

Affiliations

  1. Department of Physics, University of Wisconsin, 1150 University Avenue, Madison, Wisconsin 53706, USA

    • E. Urban
    • , T. A. Johnson
    • , T. Henage
    • , L. Isenhower
    • , D. D. Yavuz
    • , T. G. Walker
    •  & M. Saffman

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Contributions

The experimental work was carried out by E.U. and T.A.J. (who contributed equally) with assistance by T.H., L.I. and D.D.Y. Data analysis and blockade simulations were carried out by T.A.J. and M.S., calculations of Rydberg interactions were carried out by T.G.W. and M.S. and the experiment was planned and designed by T.G.W. and M.S.

Corresponding author

Correspondence to M. Saffman.

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https://doi.org/10.1038/nphys1178

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