Skip to main content
SpringerLink
Log in

Origin of quantum-mechanical complementarity probed by a ‘which-way’ experiment in an atom interferometer

  • Article
  • Published:

From Nature

View current issue Submit your manuscript

Abstract

The principle of complementarity refers to the ability of quantum-mechanical entities to behave as particles or waves under different experimental conditions. For example, in the famous double-slit experiment, a single electron can apparently pass through both apertures simultaneously, forming an interference pattern. But if a ‘which-way’ detector is employed to determine the particle's path, the interference pattern is destroyed. This is usually explained in terms of Heisenberg's uncertainty principle, in which the acquisition of spatial information increases the uncertainty in the particle's momentum, thus destroying the interference. Here we report a which-way experiment in an atom interferometer in which the ‘back action’ of path detection on the atom's momentum is too small to explain the disappearance of the interference pattern. We attribute it instead to correlations between the which-way detector and the atomic motion, rather than to the uncertainty principle.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Figure 1: Scheme of the atom interferometer.
Figure 2: Spatial fringe pattern in the far field of the interferometer.
Figure 3: Storage of which-way information.
Figure 4: Same as Fig. 2a, but with which-way information stored in the internal atomic state.

Similar content being viewed by others

References

  1. Bohr, N. in Albert Einstein: Philosopher-Scientist (ed. Schilpp, P. A.) 200–241 (Library of Living Philosophers, Evanston, (1949)); reprinted in Quantum Theory and Measurement (eds Wheeler, J. A. & Zurek, W. H.) 9–49 (Princeton Univ. Press, (1983)).

    Google Scholar 

  2. Feynman, R., Leighton, R. & Sands, M. in The Feynman Lectures on Physics Vol. III, Ch. I (Addison Wesley, Reading, (1965)).

    MATH  Google Scholar 

  3. Scully, M. O., Englert, B. G. & Walther, H. Quantum optical tests of complementarity. Nature 351, 111–116 (1991).

    Article  ADS  Google Scholar 

  4. Haroche, S. in High-resolution Laser Spectroscopy (ed. Shimoda, K.) 253–313 (Topics in Applied Physics, Vol. 13, Springer, (1976)).

    Book  Google Scholar 

  5. Rauch, H. et al. Verification of coherent spinor rotation of fermions. Phys. Lett. A 54, 425–427 (1975).

    Article  ADS  Google Scholar 

  6. Badurek, G., Rauch, H. & Tuppinger, D. Neutron interferometric double-resonance experiment. Phys. Rev. A 34, 2600–2608 (1986).

    Article  ADS  CAS  Google Scholar 

  7. Storey, P., Tan, S., Collett, M. & Walls, D. Path detection and the uncertainty principle. Nature 367, 626–628 (1994).

    Article  ADS  Google Scholar 

  8. Englert, B. G., Scully, M. O. & Walther, H. Complementarity and uncertainty. Nature 375, 367–368 (1995).

    Article  ADS  CAS  Google Scholar 

  9. Storey, E. P., Tan, S. M., Collett, M. J. & Walls, D. F. Complementarity and uncertainty. Nature 375, 368 (1995).

    Article  ADS  CAS  Google Scholar 

  10. Wiseman, H. & Harrison, F. Uncertainty over complementarity? Nature 377, 584 (1995).

    Article  ADS  CAS  Google Scholar 

  11. Wiseman, H. M. et al. Nonlocal momentum transfer in welcher weg measurements. Phys. Rev. A 56, 55–75 (1997).

    Article  ADS  CAS  Google Scholar 

  12. Eichmann, U. et al. Young's interference experiment with light scattered from two atoms. Phys. Rev. Lett. 70, 2359–2362 (1993).

    Article  ADS  CAS  Google Scholar 

  13. Cohen-Tannoudji, C. Effect of non-resonant irradiation on atomic energy levels. Metrologia 13, 161–166 (1977); reprinted in Cohen-Tannoudji, C. Atoms in Electromagnetic Fields 343–348 (World Scientific, London, (1994)).

    Google Scholar 

  14. Kunze, S., Dürr, S. & Rempe, G. Bragg scattering of slow atoms from a standing light wave. Europhys. Lett. 34, 343–348 (1996).

    Article  ADS  CAS  Google Scholar 

  15. Kunze, S. et al. Standing wave diffraction with a beam of slow atoms. J. Mod. Opt. 44, 1863–1881 (1997).

    Article  ADS  CAS  Google Scholar 

  16. Bernhardt, A. F. & Shore, B. W. Coherent atomic deflection by resonant standing waves. Phys. Rev. A 23, 1290–1301 (1981).

    Article  ADS  CAS  Google Scholar 

Download references

Acknowledgements

We thank S. Kunze for discussions. This work was supported by the Deutsche Forschungsgemeinschaft.

Author information

Authors and Affiliations

  1. Fakultät für Physik, Universität Konstanz, Konstanz, 78457, Germany

    S. Dürr, T. Nonn & G. Rempe

Authors
  1. S. Dürr
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. T. Nonn
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. G. Rempe
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to G. Rempe.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Dürr, S., Nonn, T. & Rempe, G. Origin of quantum-mechanical complementarity probed by a ‘which-way’ experiment in an atom interferometer. Nature 395, 33–37 (1998). https://doi.org/10.1038/25653

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1038/25653

  • Springer Nature Limited

This article is cited by

Search

Navigation