Atomic Hong–Ou–Mandel experiment

Abstract

Two-particle interference is a fundamental feature of quantum mechanics, and is even less intuitive than wave–particle duality for a single particle. In this duality, classical concepts—wave or particle—are still referred to, and interference happens in ordinary space-time. On the other hand, two-particle interference takes place in a mathematical space that has no classical counterpart. Entanglement lies at the heart of this interference, as it does in the fundamental tests of quantum mechanics involving the violation of Bell's inequalities1,2,3,4. The Hong, Ou and Mandel experiment5 is a conceptually simpler situation, in which the interference between two-photon amplitudes also leads to behaviour impossible to describe using a simple classical model. Here we report the realization of the Hong, Ou and Mandel experiment using atoms instead of photons. We create a source that emits pairs of atoms, and cause one atom of each pair to enter one of the two input channels of a beam-splitter, and the other atom to enter the other input channel. When the atoms are spatially overlapped so that the two inputs are indistinguishable, the atoms always emerge together in one of the output channels. This result opens the way to testing Bell's inequalities involving mechanical observables of massive particles, such as momentum, using methods inspired by quantum optics6,7, and to testing theories of the quantum-to-classical transition8,9,10,11. Our work also demonstrates a new way to benchmark non-classical atom sources12,13 that may be of interest for quantum information processing14 and quantum simulation15.

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Figure 1: Schematic of the experiment.
Figure 2: Velocity distribution of the twin atoms.
Figure 3: HOM dip in the cross-correlation function.

References

  1. 1

    Bell, J. S. On the Einstein-Podolsky-Rosen paradox. Physics 1, 195–200 (1964).

    MathSciNet  Article  Google Scholar 

  2. 2

    Aspect, A. Bell's inequality test: more ideal than ever. Nature 398, 189–190 (1999).

    ADS  CAS  Article  Google Scholar 

  3. 3

    Giustina, M. et al. Bell violation using entangled photons without the fair-sampling assumption. Nature 497, 227–230 (2013).

    ADS  CAS  Article  Google Scholar 

  4. 4

    Christensen, B. G. et al. Detection-loophole-free test of quantum nonlocality, and applications. Phys. Rev. Lett. 111, 130406 (2013).

    ADS  CAS  Article  Google Scholar 

  5. 5

    Hong, C. K., Ou, Z. Y. & Mandel, L. Measurement of subpicosecond time intervals between two photons by interference. Phys. Rev. Lett. 59, 2044–2046 (1987).

    ADS  CAS  Article  Google Scholar 

  6. 6

    Rarity, J. G. & Tapster, P. R. Experimental violation of Bell's inequality based on phase and momentum. Phys. Rev. Lett. 64, 2495–2498 (1990).

    ADS  CAS  Article  Google Scholar 

  7. 7

    Lewis-Swan, R. J. & Kheruntsyan, K. V. Motional-state Bell inequality test with ultracold atoms. Preprint at http://arXiv.org/abs/1411.0191 (2014).

  8. 8

    Penrose, R. Quantum computation, entanglement and state reduction. Phil. Trans. R. Soc. Lond. A 356, 1927–1939 (1998).

    ADS  MathSciNet  Article  Google Scholar 

  9. 9

    Zurek, W. H. Decoherence, einselection, and the quantum origins of the classical. Rev. Mod. Phys. 75, 715–775 (2003).

    ADS  MathSciNet  Article  Google Scholar 

  10. 10

    Schlosshauer, M. Decoherence, the measurement problem, and interpretations of quantum mechanics. Rev. Mod. Phys. 76, 1267–1305 (2005).

    ADS  Article  Google Scholar 

  11. 11

    Leggett, A. J. How far do EPR-Bell experiments constrain physical collapse theories? J. Phys. A 40, 3141–3149 (2007).

    ADS  MathSciNet  Article  Google Scholar 

  12. 12

    Bücker, R. et al. Twin-atom beams. Nature Phys. 7, 608–611 (2011).

    ADS  Article  Google Scholar 

  13. 13

    Kaufman, A. M. et al. Two-particle quantum interference in tunnel-coupled optical tweezers. Science 345, 306–309 (2014).

    ADS  MathSciNet  CAS  Article  Google Scholar 

  14. 14

    Nielsen, M. A. & Chuang, I. L. Quantum Computation and Quantum Information (Cambridge Univ. Press, 2000).

    Google Scholar 

  15. 15

    Kitagawa, T., Aspect, A., Greiner, M. & Demler, E. Phase-sensitive measurements of order parameters for ultracold atoms through two-particle interferometry. Phys. Rev. Lett. 106, 115302 (2011).

    ADS  Article  Google Scholar 

  16. 16

    Ou, Z. Y. Multi-Photon Quantum Interference (Springer, 2007).

    Google Scholar 

  17. 17

    Grynberg, G., Aspect, A. & Fabre, C. Introduction to Quantum Optics: From the Semiclassical Approach to Quantized Light (Cambridge Univ. Press, 2010).

    Google Scholar 

  18. 18

    Bonneau, M. et al. Tunable source of correlated atom beams. Phys. Rev. A 87, 061603 (2013).

    ADS  Article  Google Scholar 

  19. 19

    Cronin, A. D., Schmiedmayer, J. & Pritchard, D. E. Optics and interferometry with atoms and molecules. Rev. Mod. Phys. 81, 1051–1129 (2009).

    ADS  CAS  Article  Google Scholar 

  20. 20

    Schellekens, M. et al. Hanbury Brown Twiss effect for ultracold quantum gases. Science 310, 648–651 (2005).

    ADS  CAS  Article  Google Scholar 

  21. 21

    Hilligsøe, K. M. & Mølmer, K. Phase-matched four-wave mixing and quantum beam splitting of matter waves in a periodic potential. Phys. Rev. A 71, 041602 (2005).

    ADS  Article  Google Scholar 

  22. 22

    Campbell, G. K. et al. Parametric amplification of scattered atom pairs. Phys. Rev. Lett. 96, 020406 (2006).

    ADS  Article  Google Scholar 

  23. 23

    Gross, C. et al. Atomic homodyne detection of continuous-variable entangled twin-atom states. Nature 480, 219–223 (2011).

    ADS  CAS  Article  Google Scholar 

  24. 24

    Lücke, B. et al. Twin matter waves for interferometry beyond the classical limit. Science 334, 773–776 (2011).

    ADS  Article  Google Scholar 

  25. 25

    Bookjans, E., Hamley, C. & Chapman, M. Strong quantum spin correlations observed in atomic spin mixing. Phys. Rev. Lett. 107, 210406 (2011).

    ADS  Article  Google Scholar 

  26. 26

    Lewis-Swan, R. J. & Kheruntsyan, K. V. Proposal for demonstrating the Hong–Ou–Mandel effect with matter waves. Nature Commun. 5, 3752 (2014).

    ADS  CAS  Article  Google Scholar 

  27. 27

    Beugnon, J. et al. Quantum interference between two single photons emitted by independently trapped atoms. Nature 440, 779–782 (2006).

    ADS  CAS  Article  Google Scholar 

  28. 28

    Lang, C. et al. Correlations, indistinguishability and entanglement in Hong–Ou–Mandel experiments at microwave frequencies. Nature Phys. 9, 345–348 (2013).

    ADS  CAS  Article  Google Scholar 

  29. 29

    Bocquillon, E. et al. Coherence and indistinguishability of single electrons emitted by independent sources. Science 339, 1054–1057 (2013).

    ADS  CAS  Article  Google Scholar 

  30. 30

    Dubois, J. et al. Minimal-excitation states for electron quantum optics using levitons. Nature 502, 659–663 (2013).

    ADS  CAS  Article  Google Scholar 

  31. 31

    Andersson, E., Fontenelle, M. & Stenholm, S. Quantum statistics of atoms in microstructures. Phys. Rev. A 59, 3841–3850 (1999).

    ADS  CAS  Article  Google Scholar 

  32. 32

    Jaskula, J.-C. et al. Sub-Poissonian number differences in four-wave mixing of matter waves. Phys. Rev. Lett. 105, 190402 (2010).

    ADS  Article  Google Scholar 

  33. 33

    Rarity, J. G. & Tapster, P. R. Fourth-order interference in parametric downconversion. J. Opt. Soc. Am. B 6, 1221–1226 (1989).

    ADS  CAS  Article  Google Scholar 

  34. 34

    Treps, N., Delaubert, V., Maître, A., Courty, J. M. & Fabre, C. Quantum noise in multipixel image processing. Phys. Rev. A 71, 013820 (2005).

    ADS  Article  Google Scholar 

  35. 35

    Morizur, J.-F., Armstrong, S., Treps, N., Janousek, J. & Bachor, H.-A. Spatial reshaping of a squeezed state of light. Eur. Phys. J. D 61, 237–239 (2011).

    ADS  CAS  Article  Google Scholar 

  36. 36

    Ou, Z. Y. Quantum theory of fourth-order interference. Phys. Rev. A 37, 1607–1619 (1988).

    ADS  CAS  Article  Google Scholar 

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Acknowledgements

We thank J. Ruaudel and M. Bonneau for contributions to the early steps of the experiment. We also thank K. Kheruntsyan, J. Chwedenczuk and P. Deuar for discussions. We acknowledge funding by IFRAF, Triangle de la Physique, Labex PALM, ANR (PROQUP, QEAGE), FCT (scholarship SFRH/BD/74352/2010 co-financed by ESF, POPH/QREN and EU to R.L.) and EU (ERC grant 267775, QUANTATOP, and Marie Curie CIG 618760, CORENT).

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All authors contributed extensively to this work.

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Correspondence to R. Lopes or M. Cheneau.

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The authors declare no competing financial interests.

Extended data figures and tables

Extended Data Figure 1 HOM dip visibility as a function of the integration volumes.

a, Visibility V as a function of the longitudinal integration interval Δvz. The transverse integration interval is kept constant at Δv = 0.48 cm s−1. b, Visibility as a function of the transverse integration interval Δv. The longitudinal integration interval is kept constant at Δvz = 0.28 cm s−1. The red points mark the values discussed in the main text. Error bars denote the standard deviation of the statistical ensemble.

Extended Data Figure 2 Averaged number of incident atoms over the HOM dip.

a, Averaged atom number detected in , nc, as a function of the propagation time τ. The mean value of nc(τ) is 0.20 with a standard deviation of 0.01. b, Averaged atom number detected in , nd, as a function of the propagation time τ. The mean value of nd(τ) is 0.19 with a standard deviation of 0.01. c, The cross-correlation between the output ports c and d (solid blue circles), displaying the HOM dip, is compared to 〈nc〉 · 〈nd〉 (open grey circles). Error bars denote the standard deviation of the statistical ensemble.

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Lopes, R., Imanaliev, A., Aspect, A. et al. Atomic Hong–Ou–Mandel experiment. Nature 520, 66–68 (2015). https://doi.org/10.1038/nature14331

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