Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Implementation of a quantum search algorithm on a quantum computer


In 1982 Feynman1 observed that quantum-mechanical systems have an information-processing capability much greater than that of corresponding classical systems, and could thus potentially be used to implement a new type of powerful computer. Three years later Deutsch2 described a quantum-mechanical Turing machine, showing that quantum computers could indeed be constructed. Since then there has been extensive research in this field, but although the theory is fairly well understood, actually building a quantum computer has proved extremely difficult. Only two methods have been used to demonstrate quantum logic gates: ion traps3,4 and nuclear magnetic resonance (NMR)5,6. NMR quantum computers have recently been used to solve a simple quantum algorithm—the two-bit Deutsch problem7,8. Here we show experimentally that such a computer can be used to implement a non-trivial fast quantum search algorithm initially developed by Grover9,10, which can be conducted faster than a comparable search on a classical computer.

Your institute does not have access to this article

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: A quantum circuit for the implementation of a quantum search algorithm on a two-qubit computer.
Figure 2: NMR pulse sequence used to implement U f a b .
Figure 3: Experimental spectra from our NMR quantum computer.


  1. Feynman, R. P. Simulating physics with computers. Int. J. Theor. Phys. 21, 467–488 (1982).

    MathSciNet  Article  Google Scholar 

  2. Deutsch, D. Quantum-theory, the Church–Turing principle and the universal quantum computer. Proc. R. Soc. Lond. A 400, 97–117 (1985).

    ADS  MathSciNet  Article  Google Scholar 

  3. Cirac, J. I. & Zoller, P. Quantum computations with cold trapped ions. Phys. Rev. Lett. 74, 4091–4094 (1995).

    ADS  CAS  Article  Google Scholar 

  4. Monroe, C., Meekhof, D. M., King, B. E., Itano, W. M. & Wineland, D. J. Demonstration of a fundamental quantum logic gate. Phys. Rev. Lett. 75, 4714–4715 (1995).

    ADS  MathSciNet  CAS  Article  Google Scholar 

  5. Cory, D. G., Fahmy, A. F. & Havel, T. F. Ensemble quantum computing by NMR spectroscopy. Proc. Natl Acad. Sci. USA 94, 1634–1639 (1997).

    ADS  CAS  Article  Google Scholar 

  6. Gershenfeld, N. A. & Chuang, I. L. Bulk spin-resonance quantum computation. Science 275, 350–356 (1997).

    MathSciNet  CAS  Article  Google Scholar 

  7. Jones, J. A. & Mosca, M. Implementation of a quantum algorithm to solve Deutsch's problem on a nuclear magnetic resonance quantum computer. J. Chem. Phys. (in the press); also LANL preprint quant-ph/9801027.

  8. Chuang, I. L., Vandersypen, L. M. K., Zhou, X., Leung, D. W. & Lloyd, S. Experimental realization of a quantum algorithm. Nature 393, 143–146 (1998); also LANL preprint quant-ph/9801037.

    ADS  CAS  Article  Google Scholar 

  9. Grover, L. K. in Proc. 28th Annual ACM Symp. on Theory of Computation 212–218 (ACM, New York, (1996)).

    Google Scholar 

  10. Grover, L. K. Quantum mechanics helps in searching for a needle in a haystack. Phys. Rev. Lett. 79, 325–328 (1997).

    ADS  CAS  Article  Google Scholar 

  11. Boyer, M., Brassard, G., Høyer, P. & Tapp, A. in Proc. 4th Workshop on Physics and Computation—PhysComp '96 (eds Toffoli, T., Biafore, M. & Leão, J.) 36–41 (New England Complex Systems Institute, Boston, MA, (1996)).

    Google Scholar 

  12. Chuang, I. L., Gershenfeld, N. & Kubinec, M. Experimental implementation of fast quantum searching. Phys. Rev. Lett. 80, 3408–3411 (1998).

    ADS  CAS  Article  Google Scholar 

  13. Laflamme, R., Knill, E., Zurek, W. H., Catasti, P. & Mariappan, S. V. S. NMR GHZ Proc. R. Soc. Lond. A (in the press).

Download references


We thank A. Ekert for discussions; J.A.J. thanks C. M. Dobson for encouragement. This is a contribution from the Oxford Centre for Molecular Sciences, which is supported by the UK EPSRC, BBSRC and MRC. M.M. thanks CESG (UK) for their support. R.H.H. thanks the Danish Research Academy for financial assistance.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Jonathan A. Jones.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Jones, J., Mosca, M. & Hansen, R. Implementation of a quantum search algorithm on a quantum computer. Nature 393, 344–346 (1998).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing