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Wheeler's delayed-choice gedanken experiment with a single atom

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Abstract

The wave–particle dual nature of light and matter and the fact that the choice of measurement determines which one of these two seemingly incompatible behaviours we observe are examples of the counterintuitive features of quantum mechanics. They are illustrated by Wheeler’s famous ‘delayed-choice’ experiment1, recently demonstrated in a single-photon experiment2. Here, we use a single ultracold metastable helium atom in a Mach–Zehnder interferometer to create an atomic analogue of Wheeler’s original proposal. Our experiment confirms Bohr’s view that it does not make sense to ascribe the wave or particle behaviour to a massive particle before the measurement takes place1. This result is encouraging for current work towards entanglement and Bell’s theorem tests in macroscopic systems of massive particles3.

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Figure 1: Schematics of Wheeler’s delayed-choice experiments.
Figure 2: Spatial and temporal locations of the output ports of the interferometer, showing the well-resolved detection locations.
Figure 3: Wheeler’s delayed-choice experiment with massive bodies.
Figure 4: Second-order correlation function of atoms arriving at the output ports of our interferometer as a function of the delay between experimental runs.

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Change history

  • 03 June 2015

    In the version of this Letter originally published, a sentence in the text describing the points in Fig. 3 was incorrect and should have read: 'The distinction between the removal (blue points) and application (red points) of the mixing π/2 pulse is very clear, as the former is ~50% irrespective of the phase ϕ, while the latter shows the expected sinusoidal dependence on ϕ, typical of a Mach–Zehnder interferometer.' This has now been corrected in all versions of the Letter.

References

  1. Wheeler, J. A. in Mathematical Foundations of Quantum Theory (ed Marlow, A. R.) (Academic Press, 1978).

    Google Scholar 

  2. Jacques, V. et al. Experimental realization of Wheeler’s delayed-choice gedanken experiment. Science 315, 966–968 (2007).

    Article  ADS  Google Scholar 

  3. Bell, J. S. Speakable and Unspeakable in Quantum Mechanics (Cambridge Univ. Press, 1987).

    MATH  Google Scholar 

  4. de Broglie, L. Recherches sur la théorie des quanta. Ann. de Phys. 3, 22–128 (1925).

    Article  ADS  Google Scholar 

  5. Davisson, C. & Germer, L. H. Diffraction of electrons by a crystal of nickel. Phys. Rev. 30, 705–740 (1927).

    Article  ADS  Google Scholar 

  6. Englert, B-G. Fringe visibility and which-way information: An inequality. Phys. Rev. Lett. 77, 2154–2157 (1996).

    Article  ADS  Google Scholar 

  7. Ma, X., Kofler, J. & Zeilinger, A. Delayed-choice gedanken experiments and their realizations. Preprint at http://arxiv.org/abs/1407.2930v1 (2014).

  8. Hellmuth, T., Walther, H., Zajonc, A. & Schleich, W. Delayed-choice experiments in quantum interference. Phys. Rev. A 35, 2532–2541 (1987).

    Article  ADS  Google Scholar 

  9. Alley, C. O., Jacubowicz, O. G. & Wickes, W. C. in Proceedings of the Second International Symposium on the Foundations of Quantum Mechanics (ed Narani, H.) 36–47 (Physics Society of Japan, 1987).

    Google Scholar 

  10. Baldzuhn, J., Mohler, E. & Martienssen, W. A wave-particle delayed-choice experiment with a single-photon state. Z. Phys. 77, 347–352 (1989).

    Article  Google Scholar 

  11. Kim, Y-H., Yu, R., Kulik, S. P., Shih, Y. & Scully, M. O. Delayed “choice” quantum eraser. Phys. Rev. Lett. 84, 1–5 (2000).

    Article  ADS  Google Scholar 

  12. Ma, X-s. et al. Experimental delayed-choice entanglement swapping. Nature Phys. 8, 479–484 (2012).

    Article  ADS  Google Scholar 

  13. Andrews, M. R. et al. Observation of interference between two Bose condensates. Science 275, 637–641 (1997).

    Article  Google Scholar 

  14. Lawson-Daku, B. J. et al. Delayed choices in atom Stern–Gerlach interferometry. Phys. Rev. A 54, 5042–5047 (1996).

    Article  ADS  Google Scholar 

  15. Kawai, T. et al. Realization of a delayed choice experiment using a multilayer cold neutron pulser. Nucl. Instrum. Methods Phys. Res. A 410, 259–263 (1998).

    Article  ADS  Google Scholar 

  16. Manning, A. G., Khakimov, R., Dall, R. G. & Truscott, A. G. A single atom source in the picokelvin regime. Phys. Rev. Lett. 113, 130403 (2014).

    Article  ADS  Google Scholar 

  17. Martin, P. J., Oldaker, B. G., Miklich, A. H. & Pritchard, D. E. Bragg scattering of atoms from a standing light wave. Phys. Rev. Lett. 60, 515–518 (1988).

    Article  ADS  Google Scholar 

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

    Article  ADS  Google Scholar 

  19. Vassen, W. et al. Cold and trapped metastable noble gases. Rev. Mod. Phys. 84, 175–210 (2012).

    Article  ADS  Google Scholar 

  20. Grangier, P., Roger, G. & Aspect, A. Experimental evidence for a photon anticorrelation effect on a beam splitter: A new light on single-photon interferences. Europhys. Lett. 1, 173–179 (1986).

    Article  ADS  Google Scholar 

  21. Durr, S., Nonn, T. & Rempe, G. Fringe visibility and which-way information in an atom interferometer. Phys. Rev. Lett. 81, 5705–5709 (1998).

    Article  ADS  Google Scholar 

  22. Schwindt, P. D., Kwiat, P. G. & Englert, B-G. Quantitative wave-particle duality and nonerasing quantum erasure. Phys. Rev. A 60, 4285–4290 (1999).

    Article  ADS  Google Scholar 

  23. Jaeger, G., Shimony, A. & Vaidman, L. Two interferometric complementarities. Phys. Rev. A 51, 54–67 (1995).

    Article  ADS  Google Scholar 

  24. Jacques, V. et al. Delayed-choice test of quantum complementarity with interfering single photons. Phys. Rev. Lett. 100, 220402 (2008).

    Article  ADS  MathSciNet  Google Scholar 

  25. Dall, R. G. et al. Observation of atomic speckle and Hanbury Brown–Twiss correlations in guided matter waves. Nature Commun. 2, 291 (2011).

    Article  ADS  Google Scholar 

  26. Dall, R. G. et al. Ideal n-body correlations with massive particles. Nature Phys. 9, 341–344 (2013).

    Article  ADS  Google Scholar 

  27. Dall, R. G. & Truscott, A. G. Bose–Einstein condensation of metastable helium in a bi-planar quadrupole Ioffe configuration trap. Opt. Commun. 270, 255–261 (2007).

    Article  ADS  Google Scholar 

  28. Dedman, C. J., Dall, R. G., Byron, L. J. & Truscott, A. G. Active cancellation of stray magnetic fields in a Bose–Einstein condensation experiment. Rev. Sci. Instrum. 78, 024703 (2007).

    Article  ADS  Google Scholar 

  29. Shlyapnikov, G. V., Walraven, J. T. M., Rahmanov, U. M. & Reynolds, M. W. Decay kinetics and Bose condensation in a gas of spin-polarized triplet helium. Phys. Rev. Lett. 73, 3247–3250 (1994).

    Article  ADS  Google Scholar 

  30. Hodgman, S. S. et al. Metastable helium: A new determination of the longest atomic excited-state lifetime. Phys. Rev. Lett. 103, 053002 (2009).

    Article  ADS  Google Scholar 

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Acknowledgements

A.G.T. acknowledges the support of the Australian Research Council through the Future Fellowship grant FT100100468. The authors would like to acknowledge the technical assistance of C. Dedman as well as C. Savage for informative discussions.

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A.G.M., R.G.D. and A.G.T. conceived the experiment. A.G.M. and R.I.K. performed the experiment and R.I.K. collected the data presented in this Letter. All authors contributed to the conceptual formulation of the physics, the interpretation of the data and writing the manuscript.

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Correspondence to A. G. Truscott.

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The authors declare no competing financial interests.

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Manning, A., Khakimov, R., Dall, R. et al. Wheeler's delayed-choice gedanken experiment with a single atom. Nature Phys 11, 539–542 (2015). https://doi.org/10.1038/nphys3343

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