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Experimental investigation of the entanglement-assisted entropic uncertainty principle

Abstract

The uncertainty principle, which bounds the uncertainties involved in obtaining precise outcomes for two complementary variables defining a quantum particle, is a crucial aspect in quantum mechanics. Recently, the uncertainty principle in terms of entropy has been extended to the case involving quantum entanglement1. With previously obtained quantum information for the particle of interest, the outcomes of both non-commuting observables can be predicted precisely, which greatly generalizes the uncertainty relation. Here, we experimentally investigated the entanglement-assisted entropic uncertainty principle for an entirely optical set-up. The uncertainty is shown to be near zero in the presence of quasi-maximal entanglement. The new uncertainty relation is further used to witness entanglement. The verified entropic uncertainty relation provides an intriguing perspective in that it implies the uncertainty principle is not only observable-dependent but is also observer-dependent2.

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Figure 1: Experimental setup.
Figure 2: Experimental results for the conditional entropies with the input state ρ1.
Figure 3: Experimental results for the entanglement witness using the input state of ρ1.
Figure 4: Experimental results for the density matrix χ of the spin-echo based quantum memory and the entropies as a function of the angle θ.

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References

  1. Berta, M., Christandl, M., Colbeck, R., Renes, J. M. & Renner, R. The uncertainty principle in the presence of quantum memory. Nature Phys. 6, 659–662 (2010).

    Article  ADS  Google Scholar 

  2. Winter, A. Coping with uncertainty. Nature Phys. 6, 640–641 (2010).

    Article  ADS  Google Scholar 

  3. Heisenberg, W. Über den anschaulichen Inhalt der quantentheoretischen Kinematik und Mechanik. Z. Phys. 43, 172–198 (1927).

    Article  ADS  Google Scholar 

  4. Robertson, H. P. The uncertainty principle. Phys. Rev. 34, 163–164 (1929).

    Article  ADS  Google Scholar 

  5. Biłynicki-Birula, I. & Mycielski, J. Uncertainty relations for information entropy in wave mechanics. Commun. Math. Phys. 44, 129–132 (1975).

    Article  ADS  MathSciNet  Google Scholar 

  6. Deutsch, D. Uncertainty in quantum measurements. Phys. Rev. Lett. 50, 631–633 (1983).

    Article  ADS  MathSciNet  Google Scholar 

  7. Kraus, K. Complementary observables and uncertainty relations. Phys. Rev. D 35, 3070–3075 (1987).

    Article  ADS  MathSciNet  Google Scholar 

  8. Maassen, H. & Uffink, J. B. M. Generalized entropic uncertainty relations. Phys. Rev. Lett. 60, 1103–1106 (1988).

    Article  ADS  MathSciNet  Google Scholar 

  9. Einstein, A., Podolsky, B. & Rosen, N. Can quantum mechanical description of physical reality be considered complete? Phys. Rev. 47, 777–780 (1935).

    Article  ADS  Google Scholar 

  10. Popper, K. R. Zur Kritik der Ungenauigkeitsrelationen. Naturwissenschaften 22, 807–808 (1934).

    Article  ADS  Google Scholar 

  11. Kim, Y. H. & Shih, Y. Experimental realization of Popper’s experiment: Violation of the uncertainty principle? Found. Phys. 29, 1849–1861 (1999).

    Article  Google Scholar 

  12. Reid, M. D. & Drummond, P. D. Quantum correlations of phase in nondegenerate parametric oscillation. Phys. Rev. Lett. 60, 2731–2733 (1988).

    Article  ADS  Google Scholar 

  13. Reid, M. D. Demonstration of the Einstein–Podolsky–Rosen paradox using nondegenerate parametric amplification. Phys. Rev. A 40, 913–923 (1989).

    Article  ADS  Google Scholar 

  14. Ou, Z. Y., Pereira, S. F., Kimble, H. J. & Peng, K. C. Realization of the Einstein–Podolsky–Rosen paradox for continuous-variables. Phys. Rev. Lett. 68, 3663–3666 (1992).

    Article  ADS  Google Scholar 

  15. Hofmann, H. F. & Takeuchi, S. Violation of local uncertainty relations as a signature of entanglement. Phys. Rev. A. 68, 032103 (2003).

    Article  ADS  MathSciNet  Google Scholar 

  16. Howell, J. C., Bennink, R. S., Bentley, S. J. & Boyd, R. W. Realization of the Einstein–Podolsky–Rosen paradox using momentum- and position-entangled photons from spontaneous parametric down conversion. Phys. Rev. Lett. 92, 210403 (2004).

    Article  ADS  Google Scholar 

  17. Bowen, W. P., Schnabel, R., Lam, P. K. & Ralph, T. C. Experimental investigation of criteria for continuous variable entanglement. Phys. Rev. Lett. 90, 043601 (2003).

    Article  ADS  Google Scholar 

  18. Renes, J. M. & Boileau, J. C. Conjectured strong complementary information tradeoff. Phys. Rev. Lett. 103, 020402 (2009).

    Article  ADS  Google Scholar 

  19. Devetak, I. & Winter, A. Distillation of secret key and entanglement from quantum states. Proc. R. Soc. A 461, 207–235 (2005).

    Article  ADS  MathSciNet  Google Scholar 

  20. Fano, R. Transimission of Information: A Statistical Theory of Communications (Cambridge, Mass., M.I.T. Press, 1961).

    Google Scholar 

  21. Kwiat, P. G., Waks, E., White, A. G., Appelbaum, I. & Eberhard, P. H. Ultrabright source of polarization-entangled photons. Phys. Rev. A 60, R773–R776 (1999).

    Article  ADS  Google Scholar 

  22. Xu, J-S., Li, C-F. & Guo, G-C. Generation of a high-visibility four-photon entangled state and realization of a four-party quantum communication complexity scenario. Phys. Rev. A 74, 052311 (2006).

    Article  ADS  Google Scholar 

  23. Aiello, A., Puentes, G., Voigt, D. & Woerdman, J. P. Maximally entangled mixed-state generation via local operations. Phys. Rev. A 75, 062118 (2007).

    Article  ADS  MathSciNet  Google Scholar 

  24. James, D. F. V., Kwiat, P. G., Munro, W. J. & White, A. G. Measurement of qubits. Phys. Rev. A 64, 052312 (2001).

    Article  ADS  Google Scholar 

  25. Wootters, W. K. Entanglement of formation of an arbitrary state of two qubits. Phys. Rev. Lett. 80, 2245–2248 (1998).

    Article  ADS  Google Scholar 

  26. Prevedel, R., Hamel, D. R., Colbeck, R., Fisher, K. & Resch, K. J. Experimental investigation of the uncertainty principle in the presence of quantum memory. Nature Phys.doi:10.1038/nphys2048 (2011).

  27. Chuang, I. L. & Nielsen, M. A. Prescription for experimental determination of the dynamics of a quantum black box. J. Mod. Opt. 44, 2455–2467 (1997).

    Article  ADS  Google Scholar 

  28. O’Brien, J. L. et al. Quantum process tomography of a controlled-NOT gate. Phys. Rev. Lett. 93, 080502 (2004).

    Article  ADS  Google Scholar 

  29. Altepeter, J. B., Jeffrey, E. R. & Kwiat, P. G. in Advances in Atomic, Molecular and Optical Physics Vol. 52 (eds Berman, P. & Lin, C.) 107–161 (Elsevier, 2005).

    Google Scholar 

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Acknowledgements

This work was supported by the National Basic Research Program of China (Grants No. 2011CB921200), National Natural Science Foundation of China (Grant Nos 11004185, 60921091, 10874162), and the China Postdoctoral Science Foundation (Grant No. 20100470836). The CQT is funded by the Singapore MoE and the NRF as part of the Research Centres of Excellence programme.

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Authors

Contributions

C-F.L. and J-S.X. designed the experiment. C-F.L. supervised the project. J-S.X. and X-Y.X. performed the experiment. J-S.X. analysed the theoretical prediction and experimental data. K.L. and G-C.G. contributed to the theoretical analysis. X-Y.X. drew the sketch of the experimental setup. J-S.X. wrote the paper. All authors commented on the manuscript.

Corresponding author

Correspondence to Chuan-Feng Li.

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The authors declare no competing financial interests.

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Li, CF., Xu, JS., Xu, XY. et al. Experimental investigation of the entanglement-assisted entropic uncertainty principle. Nature Phys 7, 752–756 (2011). https://doi.org/10.1038/nphys2047

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