Letters to Nature

Nature 393, 344-346 (28 May 1998) | doi:10.1038/30687; Received 6 March 1998; Accepted 23 April 1998

Implementation of a quantum search algorithm on a quantum computer

Jonathan A. Jones1,2, Michele Mosca2,3 & Rasmus H. Hansen2

  1. Oxford Centre for Molecular Sciences, New Chemistry Laboratory, South Parks Road, Oxford OX1 3QT, UK
  2. Centre for Quantum Computation, Clarendon Laboratory, Parks Road, Oxford OX1 3PU, UK
  3. Mathematical Institute, 2429 St Giles', Oxford OX1 3LB, UK

Correspondence to: Jonathan A. Jones1,2 Correspondence and requests for materials should be addressed to J.A.J. (e-mail: Email: jones@bioch.ox.ac.uk).

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.