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Realization of collective strong coupling with ion Coulomb crystals in an optical cavity

Nature Physics volume 5, pages 494498 (2009) | Download Citation

Abstract

Cavity quantum electrodynamics (CQED) focuses on understanding the interactions between matter and the electromagnetic field in cavities at the quantum level1,2. In the past years, CQED has attracted attention3,4,5,6,7,8,9 especially owing to its importance for the field of quantum information10. At present, photons are the best carriers of quantum information between physically separated sites11,12 and quantum-information processing using stationary qubits10 is most promising, with the furthest advances having been made with trapped ions13,14,15. The implementation of complex quantum-information-processing networks11,12 hence requires devices to efficiently couple photons and stationary qubits. Here, we present the first CQED experiments demonstrating that the collective strong-coupling regime2 can be reached in the interaction between a solid in the form of an ion Coulomb crystal16 and an optical field. The obtained coherence times are in the millisecond range and indicate that Coulomb crystals positioned inside optical cavities are promising for realizing a variety of quantum-information devices, including quantum repeaters12 and quantum memories for light17,18. Moreover, cavity optomechanics19 using Coulomb crystals might enable the exploration of similar phenomena investigated using more traditional solids, such as micro-mechanical oscillators20.

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References

  1. 1.

    Berman, P. (ed.) Cavity Quantum Electrodynamics (Academic, 1994).

  2. 2.

    & Exploring the Quantum: Atoms, Cavities and Photons (Oxford Univ. Press, 2006).

  3. 3.

    , , , & Continuous generation of single photons with controlled waveform in an ion-trap cavity system. Nature 431, 1075–1078 (2004).

  4. 4.

    et al. Cavity cooling of a single atom. Nature 428, 50–52 (2004).

  5. 5.

    et al. Observation of strong coupling between one atom and a monolithic resonator. Nature 443, 671–674 (2006).

  6. 6.

    , , , & Vacuum Rabi splitting in semiconductors. Nature Phys. 2, 81–90 (2006).

  7. 7.

    et al. Strong coupling of a single photon to a superconducting qubit using circuit quantum electrodynamics. Nature 431, 162–167 (2004).

  8. 8.

    et al. Cavity QED with a Bose–Einstein condensate. Nature 450, 268–271 (2007).

  9. 9.

    et al. Strong atom-field coupling for Bose–Einstein condensates in an optical cavity on a chip. Nature 450, 272–276 (2007).

  10. 10.

    & Quantum Computation and Quantum Information (Cambridge Univ. Press, 2000).

  11. 11.

    , , & Quantum state transfer and entanglement distribution among distant nodes in a quantum network. Phys. Rev. Lett. 78, 3221–3224 (1997).

  12. 12.

    , , & Long distance quantum communication with atomic ensembles and linear optics. Nature 414, 413–418 (2001).

  13. 13.

    et al. Creation of a six-atom ‘Schrödinger cat’ state. Nature 438, 639–642 (2005).

  14. 14.

    et al. Scalable multiparticle entanglement of trapped ions. Nature 438, 643–646 (2005).

  15. 15.

    , , & Towards fault-tolerant quantum computing with trapped ions. Nature Phys. 4, 463–466 (2008).

  16. 16.

    , , , & Atomic-ion Coulomb clusters in an ion trap. Phys. Rev. Lett. 59, 2935–2938 (1987).

  17. 17.

    , & Entanglement of atomic ensembles by trapping correlated photon states. Phys. Rev. Lett. 84, 4232–4236 (2000).

  18. 18.

    , , & Interfacing collective atomic excitations and single photons. Phys. Rev. Lett. 98, 183601 (2007).

  19. 19.

    , , & Cavity optomechanics with a Bose–Einstein condensate. Science 322, 235–238 (2008).

  20. 20.

    & Cavity optomechanics: Back-action at the mesoscale. Science 321, 1172–1176 (2008).

  21. 21.

    , , , & A single ion as a nanoscopic probe of an optical field. Nature 414, 49–51 (2001).

  22. 22.

    et al. Spontaneous emission lifetime of a single trapped Ca+ ion in a high finesse cavity. Phys. Rev. Lett. 92, 203002 (2004).

  23. 23.

    , & Observation of normal-mode splitting for an atom in an optical cavity. Phys. Rev. Lett. 68, 1132–1135 (1992).

  24. 24.

    , , & Squeezing with cold atoms. Europhys. Lett. 36, 93–98 (1996).

  25. 25.

    , , , & Large ion crystals in a linear Paul trap. Phys. Rev. Lett. 81, 2878–2881 (1998).

  26. 26.

    et al. Loading of large ion Coulomb crystals into a linear Paul trap incorporating an optical cavity. Appl. Phys. B 93, 373–379 (2008).

  27. 27.

    , , & Temperature, ordering, and equilibrium with time-dependent confining forces. Proc. Natl Acad. Sci. USA 97, 10697–10700 (2001).

  28. 28.

    et al. The coherence of qubits based on single Ca+ ions. J. Phys. B 36, 623–636 (2003).

  29. 29.

    & Quantum-state transfer between fields and atoms in electromagnetically induced transparency. Phys. Rev. A 69, 043810 (2004).

  30. 30.

    , , & Radio frequency field-induced persistent long-range ordered structures in two-species ion Coulomb crystals. J. Phys. B 40, F223–F229 (2007).

  31. 31.

    , , & Structural properties of two-component coulomb crystals in linear Paul traps. Phys. Rev. Lett. 86, 1994–1997 (2001).

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Acknowledgements

We acknowledge financial support from the Carlsberg Foundation and the Danish Natural Science Research Council through the ESF EuroQUAM project CMMC. We thank A. Mortensen, J. L. Sørensen and M. Langkilde-Lauesen for their contributions in an earlier phase of the project and P. Grangier for useful comments.

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Author notes

    • Peter F. Herskind
    •  & Aurélien Dantan

    These authors contributed equally to this work

Affiliations

  1. QUANTOP, Danish National Research Foundation Center for Quantum Optics, Department of Physics and Astronomy, University of Aarhus, DK-8000 Aarhus C, Denmark

    • Peter F. Herskind
    • , Aurélien Dantan
    • , Joan P. Marler
    • , Magnus Albert
    •  & Michael Drewsen

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Correspondence to Michael Drewsen.

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https://doi.org/10.1038/nphys1302

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