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Experimental Implementations of Quantum Paradoxes

  • G. A. D. BriggsEmail author

Abstract

Remarkable progress is being made in experiments that highlight the distinctive predictions of quantum mechanics. The Leggett-Garg inequality was devised to test for macrorealism (Leggett and Garg in Phys. Rev. Lett. 54:857–860, 1985). Various experiments have been performed, including one with non-invasive measurements in the kind of way that was originally envisaged, using spins in phosphorous impurities in silicon (Knee et al. in Nat. Commun. 3:606, 2012). This has led to fresh understanding of what kind of realism is excluded by the result. The quantum three-box paradox (Aharonov and Vaidman in J. Phys. A, Math. Gen. 24:2315–2328, 1991) provides a further test, which can be re-expressed in terms of the Leggett-Garg inequality. This has been experimentally implemented with projective measurements using an NV centre in diamond, yielding results 7.8 standard deviations beyond a classical bound (George et al. in Proc. Natl. Acad. Sci. USA 110:3777–3781, 2013). [Editor’s note: for a video of the talk given by Prof. Briggs at the Aharonov-80 conference in 2012 at Chapman University, see quantum.chapman.edu/talk-18.]

Keywords

Projective Measurement Microwave Pulse Weak Measurement Unit Probability Solid Immersion Lens 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgements

I gladly acknowledge my co-authors of [3] and also [16] for the experiments and results and their interpretation, and for many stimulating discussions about the further implications. Those papers should be taken as definitive in the event of any inadvertent discrepancy, though I take responsibility for additional views which go beyond the papers. I thank Richard George for helpful comments on the manuscript, and the John Templeton Foundation, together with the other agencies acknowledged in the papers, for funding the research.

References

  1. 1.
    D.Z. Albert, Y. Aharonov, S. D’Amato, Curious new statistical prediction of quantum-mechanics. Phys. Rev. Lett. 54, 5–7 (1985) MathSciNetADSCrossRefGoogle Scholar
  2. 2.
    Y. Aharonov, L. Vaidman, Complete description of a quantum system at a given time. J. Phys. A, Math. Gen. 24, 2315–2328 (1991) MathSciNetADSCrossRefGoogle Scholar
  3. 3.
    R.E. George et al., Opening up three quantum boxes causes classically undetectable wavefunction collapse. Proc. Natl. Acad. Sci. USA 110, 3777–3781 (2013) ADSCrossRefGoogle Scholar
  4. 4.
    Y. Aharonov, D.Z. Albert, L. Vaidman, How the result of a measurement of a component of the spin of a spin-1/2 particle can turn out to be 100. Phys. Rev. Lett. 60, 1351–1354 (1988) ADSCrossRefGoogle Scholar
  5. 5.
    N. Aharon, L. Vaidman, Quantum advantages in classically defined tasks. Phys. Rev. A 77, 052310 (2008) ADSCrossRefGoogle Scholar
  6. 6.
    Y. Aharonov, D. Rohrlich, Quantum Paradoxes: Quantum Theory for the Perplexed (Wiley-VCH, New York, 2008) Google Scholar
  7. 7.
    K.J. Resch, J.S. Lundeen, A.M. Steinberg, Experimental realization of the quantum box problem. Phys. Lett. A 324, 125–131 (2004) ADSCrossRefzbMATHGoogle Scholar
  8. 8.
    P. Kolenderski et al., Aharon-Vaidman quantum game with a Young-type photonic qutrit. Phys. Rev. A 86, 012321 (2012) ADSCrossRefGoogle Scholar
  9. 9.
    A.J. Leggett, A. Garg, Quantum-mechanics versus macroscopic realism: is the flux there when nobody looks? Phys. Rev. Lett. 54, 857–860 (1985) MathSciNetADSCrossRefGoogle Scholar
  10. 10.
    A. Pais, Einstein and the quantum theory. Rev. Mod. Phys. 51, 863–914 (1979) MathSciNetADSCrossRefGoogle Scholar
  11. 11.
    A.J. Leggett, The quantum measurement problem. Science 307, 871–872 (2005) ADSCrossRefGoogle Scholar
  12. 12.
    J.F. Clauser, M.A. Horne, A. Shimony, R.A. Holt, Proposed experiment to test local hidden-variable theories. Phys. Rev. Lett. 23, 880–884 (1969) ADSCrossRefGoogle Scholar
  13. 13.
    A. Palacios-Laloy et al., Experimental violation of a Bell’s inequality in time with weak measurement. Nat. Phys. 6, 442–447 (2010) CrossRefGoogle Scholar
  14. 14.
    M.E. Goggin et al., Violation of the Leggett-Garg inequality with weak measurements of photons. Proc. Natl. Acad. Sci. USA 108, 1256–1261 (2011) ADSCrossRefGoogle Scholar
  15. 15.
    G. Waldherr, P. Neumann, S.F. Huelga, F. Jelezko, J. Wrachtrup, Violation of a temporal Bell inequality for single spins in a diamond defect center. Phys. Rev. Lett. 107, 090401 (2011) ADSCrossRefGoogle Scholar
  16. 16.
    G.C. Knee et al., Violation of a Leggett-Garg inequality with ideal non-invasive measurements. Nat. Commun. 3, 606 (2012) ADSCrossRefGoogle Scholar
  17. 17.
    A.J. Leggett, Experimental approaches to the quantum measurement paradox. Found. Phys. 18, 939–952 (1988) ADSCrossRefGoogle Scholar
  18. 18.
    M.M. Wilde, A. Mizel, Addressing the clumsiness loophole in a Leggett-Garg test of macrorealism. Found. Phys. 42, 256–265 (2012) MathSciNetADSCrossRefzbMATHGoogle Scholar
  19. 19.
    R.E. George et al., Opening up three quantum boxes causes classically undetectable wavefunction collapse (Supporting Information). Proc. Natl. Acad. Sci. USA 110, 3777–3781 (2013) ADSCrossRefGoogle Scholar
  20. 20.
    M.F. Pusey, J. Barrett, T. Rudolph, On the reality of the quantum state. Nat. Phys. 8, 474–477 (2012) CrossRefGoogle Scholar
  21. 21.
    M. Schlosshauer, J. Kofler, A. Zeilinger, The interpretation of quantum mechanics: from disagreement to consensus? Ann. Phys. 525(4), A51–A54 (2013) ADSCrossRefzbMATHGoogle Scholar

Copyright information

© Springer-Verlag Italia 2014

Authors and Affiliations

  1. 1.Department of MaterialsUniversity of OxfordOxfordUK

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