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.

A silicon-based nuclear spin quantum computer


Quantum computers promise to exceed the computational efficiency of ordinary classical machines because quantum algorithms allow the execution of certain tasks in fewer steps. But practical implementation of these machines poses a formidable challenge. Here I present a scheme for implementing a quantum-mechanical computer. Information is encoded onto the nuclear spins of donor atoms in doped silicon electronic devices. Logical operations on individual spins are performed using externally applied electric fields, and spin measurements are made using currents of spin-polarized electrons. The realization of such a computer is dependent on future refinements of conventional silicon electronics.

This is a preview of subscription content, access via your institution

Access options

Rent or buy this article

Prices vary by article type



Prices may be subject to local taxes which are calculated during checkout

Figure 1: Illustration of two cells in a one-dimensional array containing 31P donors and electrons in a Si host, separated by a barrier from metal gates on the surface.
Figure 2: An electric field applied to an A gate pulls the electron wavefunction away from the donor and towards the barrier, reducing the hyperfine interaction and the resonance frequency of the nucleus.
Figure 3: J gates vary the electrostatic potential barrier V between donors to enhance or reduce exchange coupling, proportional to the electron wavefunction overlap.
Figure 4: Two qubit quantum logic and spin measurement.

Similar content being viewed by others


  1. Steane, A. Quantum computing. Rep. Prog. Phys. 61, 117–173 (1998).

    Article  ADS  MathSciNet  CAS  Google Scholar 

  2. Bennett, C. H. Quantum information and computation. Physics Today 24–30 (Oct. (1995).

  3. Shor, P. W. in Proc. 35th Annu. Symp. Foundations of Computer Science (ed. Goldwasser, S.) 124–134 (IEEE Computer Society, Los Alamitos, CA, 1994).

    Book  Google Scholar 

  4. Ekert, A. & Jozsa, R. Quantum computation and Shor's factoring algorithm. Rev. Mod. Phys. 68, 733–753 (1996).

    Article  ADS  MathSciNet  CAS  Google Scholar 

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

    Article  ADS  CAS  Google Scholar 

  6. Calderbank, A. R. & Shor, P. W. Good quantum error correcting codes exist. Phys. Rev. A 54, 1098–1105 (1996).

    Article  ADS  CAS  Google Scholar 

  7. Steane, A. M. Error correcting codes in quantum theory. Phys. Rev. Lett. 77, 793–797 (1996).

    Article  ADS  MathSciNet  CAS  Google Scholar 

  8. Preskill, J. Reliable quantum computers. Proc. R. Soc. Lond. A 454, 385–410 (1998).

    Article  ADS  Google Scholar 

  9. Lloyd, S. Apotentially realizable quantum computer. Science 261, 1569–1571 (1993).

    Article  ADS  CAS  Google Scholar 

  10. DiVincenzo, D. P. Quantum computation. Science 270, 255–261 (1995).

    Article  ADS  MathSciNet  CAS  Google Scholar 

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

    Article  MathSciNet  CAS  Google Scholar 

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

    Article  ADS  CAS  Google Scholar 

  13. Loss, D. & DiVincenzo, D. P. Quantum computation with quantum dots. Phys. Rev. A 57, 120–126 (1998).

    Article  ADS  CAS  Google Scholar 

  14. Privman, V., Vagner, I. D. & Kventsel, G. Quantum computation in quantum Hall systems. Phys. Lett. A 239, 141–146 (1998)..

    Article  ADS  MathSciNet  CAS  Google Scholar 

  15. Slichter, C. P. Principles of Magnetic Resonance3rd edn, Ch 4 (Springer, Berlin, 1990).

    Book  Google Scholar 

  16. Dobers, M., Klitzing, K. v., Schneider, J., Weimann, G. & Ploog, K. Electrical detection of nuclear magnetic resonance in GaAs-AlxGa1−xAs heterostructures. Phys. Rev. Lett. 61, 1650–1653 (1988).

    Article  ADS  CAS  Google Scholar 

  17. Stich, B., Greulich-Weber, S. & Spaeth, J.-M. Electrical detection of electron nuclear double resonance in silicon. Appl. Phys. Lett. 68, 1102–1104 (1996).

    Article  ADS  CAS  Google Scholar 

  18. Kane, B. E., Pfeiffer, L. N. & West, K. W. Evidence for an electric-field-induced phase transition in a spin-polarized two-dimensional electron gas. Phys. Rev. B 46, 7264–7267 (1992).

    Article  ADS  CAS  Google Scholar 

  19. Wald, K. W., Kouwenhoven, L. P., McEuen, P. L., van der Vaart, N. C. & Foxon, C. T. Local dynamic nuclear polarization using quantum point contacts. Phys. Rev. Lett. 73, 1011–1014 (1994).

    Article  ADS  CAS  Google Scholar 

  20. Dixon, D. C., Wald, K. R., McEuen, P. L. & Melloch, M. R. Dynamic polarization at the edge of a two-dimensional electron gas. Phys. Rev. B 56, 4743–4750 (1997).

    Article  ADS  CAS  Google Scholar 

  21. CRC Handbook of Chemistry and Physics 77th edn 11–38 (CRC Press, Boca Raton, Florida, 1996).

  22. Feher, G. Electron spin resonance on donors in silicon. I. Electronic structure of donors by the electron nuclear double resonance technique. Phys. Rev. 114, 1219–1244 (1959).

    Article  ADS  CAS  Google Scholar 

  23. Wilson, D. K. & Feher, G. Electron spin resonance experiments on donors in silicon. III. Investigation of excited states by the application of uniaxial stress and their importance in relaxation processes. Phys. Rev. 124, 1068–1083 (1961).

    Article  ADS  CAS  Google Scholar 

  24. Waugh, J. S. & Slichter, C. P. Mechanism of nuclear spin-lattice relaxation in insulators at very low temperatures. Phys. Rev. B 37, 4337–4339 (1988).

    Article  ADS  CAS  Google Scholar 

  25. Kohn, W. Solid State Physics Vol. 5(eds Seitz, F. & Turnbull, D.) 257–320 (Academic, New York, 1957).

    Google Scholar 

  26. DiVincenzo, D. P. Two-bit gates are universal for quantum computation. Phys. Rev. A 51, 1015–1021 (1995).

    Article  ADS  CAS  Google Scholar 

  27. Lloyd, S. Almost any quantum logic gate is universal. Phys. Rev. Lett. 75, 346–349 (1995).

    Article  ADS  CAS  Google Scholar 

  28. Herring, C. & Flicker, M. Asymptotic exchange coupling of two hydrogen atoms. Phys. Rev. 134, A362–A366 (1964).

    Article  ADS  Google Scholar 

  29. Andres, K., Bhatt, R. N., Goalwin, P., Rice, T. M. & Walstedt, R. E. Low-temperature magnetic susceptibility of Si:P in the nonmetallic region. Phys. Rev. B 24, 244–260 (1981).

    Article  ADS  CAS  Google Scholar 

  30. Ashcroft, N. W. & Mermin, N. D. in Solid State PhysicsCh. 32 (Saunders College, Philadelphia, 1976).

    MATH  Google Scholar 

  31. Larsen, D. M. Stress dependence of the binding energy of D centers in Si. Phys. Rev. B 23, 5521–5526 (1981).

    Article  ADS  CAS  Google Scholar 

  32. Larsen, D. M. & McCann, S. Y. Variational studies of two- and three-dimensional D centers in magnetic fields. Phys. Rev. B 46, 3966–3970 (1992).

    Article  ADS  CAS  Google Scholar 

  33. Ashoori, R. C. Electrons in artificial atoms. Nature 379, 413–419 (1996).

    Article  ADS  CAS  Google Scholar 

  34. Abragam, A. Principles of Nuclear Magnetism (Oxford Univ. Press, London, 1961).

    Google Scholar 

  35. Lyding, J. W. UHV STM nanofabrication: progress, technology spin-offs, and challenges. Proc. IEEE 85, 589–600 (1997).

    Article  CAS  Google Scholar 

  36. Adams, C. S., Sigel, J. & Mlynek, J. Atom optics. Phys. Rep. 240, 143–210 (1994).

    Article  ADS  CAS  Google Scholar 

  37. Warren, W. S. The usefulness of NMR quantum computing. Science 277, 1688–1690 (1997).

    Article  CAS  Google Scholar 

Download references


This work has been supported by the Australian Research Council. I thank R.G.Clark for encouragement and E. Hellman for suggesting that the work in ref. 18 could be relevant to quantum computation.

Author information

Authors and Affiliations


Corresponding author

Correspondence to B. E. Kane.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Kane, B. A silicon-based nuclear spin quantum computer. Nature 393, 133–137 (1998).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


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