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Oversimplifying quantum factoring

Abstract

Shor’s quantum factoring algorithm exponentially outperforms known classical methods. Previous experimental implementations have used simplifications dependent on knowing the factors in advance. However, as we show here, all composite numbers admit simplification of the algorithm to a circuit equivalent to flipping coins. The difficulty of a particular experiment therefore depends on the level of simplification chosen, not the size of the number factored. Valid implementations should not make use of the answer sought.

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Figure 1: Circuit for Shor’s algorithm using the semi-classical quantum Fourier transform.
Figure 2: The circuit for the fully compiled Shor’s algorithm.
Figure 3: Experimental data from unbiased coins.

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References

  1. Shor, P. W. in Proc. 35th IEEE Symp. on the Foundations of Computer Science (FOCS) 124–134 (IEEE Computer Society, 1994)

    Google Scholar 

  2. Shor, P. W. in Proc. 37th IEEE Symp. on the Foundations of Computing (FOCS) 56–65 (IEEE Computer Society, 1996)

    Google Scholar 

  3. Aliferis, P., Gottesman, D. & Preskill, J. Accuracy threshold for postselected quantum computation. Quant. Inform. Comput. 8, 181–244 (2008)

    MathSciNet  MATH  Google Scholar 

  4. Zurek, W. H. Pointer basis of quantum apparatus: into what mixture does the wave packet collapse? Phys. Rev. D 24, 1516–1525 (1981)

    Article  ADS  MathSciNet  Google Scholar 

  5. Vandersypen, L. M. K. et al. Experimental realization of Shor’s quantum factoring algorithm using nuclear magnetic resonance. Nature 414, 883–887 (2001)

    Article  CAS  ADS  Google Scholar 

  6. Lanyon, B. P. et al. Experimental demonstration of a compiled version of Shor’s algorithm with quantum entanglement. Phys. Rev. Lett. 99, 250505 (2007)

    Article  CAS  ADS  Google Scholar 

  7. Lu, C.-Y., Browne, D. E., Yang, T. & Pan, J.-W. Demonstration of a compiled version of Shor’s quantum factoring algorithm using photonic qubits. Phys. Rev. Lett. 99, 250504 (2007)

    Article  ADS  Google Scholar 

  8. Politi, A., Matthews, J. C. F. & O’Brien, J. L. Shor’s quantum factoring algorithm on a photonic chip. Science 325, 1221 (2009)

    Article  CAS  ADS  MathSciNet  Google Scholar 

  9. Martín-López, E., Laing, A., Lawson, T., Zhou, X.-Q. & O’Brien, J. L. Experimental realization of Shor’s quantum factoring algorithm using qubit recycling. Nature Photon. 6, 773–776 (2012)

    Article  ADS  Google Scholar 

  10. Lucero, E. Computing prime factors with a Josephson phase qubit quantum processor. Nature Phys. 8, 719–723 (2012)

    Article  CAS  ADS  Google Scholar 

  11. Lenstra, A. K., Lenstra, H. W., Jr, Manasse, M. S. & Pollard, J. M. in Proc. 22nd Annual ACM Symp. on Theory of Computing (STOC) 564–572 (ACM Press, New York, 1990)

    Google Scholar 

  12. Zalka, C. Shor’s algorithm with fewer (pure) qubits. Preprint at http://arXiv.org/abs/quant-ph/0601097 (2006)

  13. Mosca, M. & Ekert, A. in Quantum Computing and Quantum Communications (ed. Williams, C. P. ) 174–188 (Vol. 1509, Lecture Notes in Computer Science, Springer, 1999)

    Book  Google Scholar 

  14. Parker, S. & Plenio, M. B. Efficient factorization with a single pure qubit and logN mixed qubits. Phys. Rev. Lett. 85, 3049–3052 (2000)

    Article  CAS  ADS  Google Scholar 

  15. Griffiths, R. B. & Niu, C. S. Semiclassical Fourier transform for quantum computation. Phys. Rev. Lett. 76, 3228–3231 (1996)

    Article  CAS  ADS  Google Scholar 

  16. Zhou, Z. & Geller, M. R. Factoring 51 and 85 with 8 qubits. Preprint at http://arXiv.org/abs/1304.0128 (2013)

  17. Zi, S. The mathematical classic of Sun Zi. In Yong, L.-L. & Se, A.-T. Fleeting Footsteps: Tracing the Conception of Arithmetic and Algebra in Ancient China (World Scientific, 2004)

    Google Scholar 

  18. Heath, T. (ed) The Thirteen Books of Euclid's Elements (Dover, 1956)

    MATH  Google Scholar 

Download references

Acknowledgements

We acknowledge support from IARPA (contract no. W911NF-10-1-0324) and from the DARPA QUEST programme (contract no. HR0011-09-C-0047). All statements of fact, opinion or conclusions contained herein are those of the authors and should not be construed as representing the official views or policies of the US Government.

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Authors and Affiliations

Authors

Contributions

J.A.S., G.S. and A.V. designed and carried out the research. G.S. performed the experiments, J.A.S. analysed the data, and A.V. carried out the number theory. J.A.S., G.S. and A.V. wrote the paper.

Corresponding author

Correspondence to John A. Smolin.

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Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary Information

This file contains N-20000, a 20,000-bit number of our own creation. (PDF 96 kb)

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Smolin, J., Smith, G. & Vargo, A. Oversimplifying quantum factoring. Nature 499, 163–165 (2013). https://doi.org/10.1038/nature12290

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