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Anderson–Mott transition in arrays of a few dopant atoms in a silicon transistor


Dopant atoms are used to control the properties of semiconductors in most electronic devices. Recent advances such as single-ion implantation1,2,3,4,5 have allowed the precise positioning of single dopants in semiconductors as well as the fabrication of single-atom transistors6,7,8,9, representing steps forward in the realization of quantum circuits10,11,12,13,14. However, the interactions between dopant atoms have only been studied in systems containing large numbers of dopants, so it has not been possible to explore fundamental phenomena such as the Anderson–Mott transition between conduction by sequential tunnelling through isolated dopant atoms, and conduction through thermally activated impurity Hubbard bands15,16,17,18. Here, we observe the Anderson–Mott transition at low temperatures in silicon transistors containing arrays of two, four or six arsenic dopant atoms that have been deterministically implanted along the channel of the device. The transition is induced by controlling the spacing between dopant atoms. Furthermore, at the critical density between tunnelling and band transport regimes, we are able to change the phase of the electron system from a frozen Wigner-like phase to a Fermi glass by increasing the temperature. Our results open up new approaches for the investigation of coherent transport, band engineering and strongly correlated systems in condensed-matter physics.

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Figure 1: Single-ion-implanted devices.
Figure 2: Anderson–Mott transition probed by means of quantum transport.
Figure 3: Thermal activation of transport.


  1. Shinada, T., Okamoto, S., Kobayashi, T. & Ohdomari, I. Enhancing semiconductor device performance using ordered dopant arrays. Nature 437, 1128–1131 (2005).

    CAS  Article  Google Scholar 

  2. Tan, K. Y. et al. Transport spectroscopy of single phosphorus donors in a silicon nanoscale transistor. Nano Lett. 10, 11–15 (2010).

    CAS  Article  Google Scholar 

  3. Persaud, A. et al. Integration of scanning probes and ion beams. Nano Lett. 5, 1087–1091 (2005).

    CAS  Article  Google Scholar 

  4. Shinada, T. et al. A reliable method for the counting and control of single ions for single-dopant controlled devices. Nanotechnology 19, 345202 (2008).

    CAS  Article  Google Scholar 

  5. Hori, M. et al. Enhancing single-ion detection efficiency by applying substrate bias voltage for deterministic single-ion doping. Appl. Phys. Exp. 4, 046501 (2011).

    Article  Google Scholar 

  6. Koenraad, P. M. & Flatté, M. E. Single dopants in semiconductors. Nature Mater. 10, 91–100 (2011).

    CAS  Article  Google Scholar 

  7. Pierre, M. et al. Single-donor ionization energies in a nanoscale CMOS channel. Nature Nanotech. 5, 133–137 (2010).

    CAS  Article  Google Scholar 

  8. Morello, A. et al. Single-shot readout of an electron spin in silicon. Nature 467, 687–691 (2010).

    CAS  Article  Google Scholar 

  9. Fuechsle, M. et al. A single atom transistor. Nature Nanotech. 7, 242–246 (2012).

    CAS  Article  Google Scholar 

  10. Hollemberg, L. C. L., Greentree, A. D., Fowler, A. G. & Wellard, C. J. Two-dimensional architectures for donor-based quantum computing. Phys. Rev. B 74, 045311 (2006).

    Article  Google Scholar 

  11. Rahman, R. et al. Atomistic simulations of adiabatic coherent electron transport in triple donor systems. Phys. Rev. B 80, 035302 (2009).

    Article  Google Scholar 

  12. Prati, E. Valley blockade quantum switching in silicon nanostructures. J. Nanosci. Nanotech. 11, 8522–8526 (2011).

    CAS  Article  Google Scholar 

  13. Leti, G. et al. Switching quantum transport in a three donors silicon fin-field effect transistor. Appl. Phys. Lett. 99, 242102 (2011).

    Article  Google Scholar 

  14. Klein, M. et al. Ternary logic implemented on a single dopant atom field effect silicon transistor. Appl. Phys. Lett. 96, 043107 (2010).

    Article  Google Scholar 

  15. Anderson, P. W. Absence of diffusion in certain random lattices. Phys. Rev. 109, 1492–1505 (1958).

    CAS  Article  Google Scholar 

  16. Mott, N. F. & Twose, W. D. The theory of impurity conduction. Adv. Phys. 10, 107–163 (1961).

    CAS  Article  Google Scholar 

  17. Mott, N. F. Metal–Insulator Transitions (Taylor and Francis, 1974).

  18. Hubbard, J. Electron correlations in narrow energy bands. Proc. R. Soc. Lond. A 276, 238–257 (1963).

    Article  Google Scholar 

  19. Ono, Y. et al. Conductance modulation by individual acceptors in Si nanoscale field-effect transistors. Appl. Phys. Lett. 90, 102106 (2007).

    Article  Google Scholar 

  20. Lansbergen, G. P. et al. Gate-induced quantum-confinement transition of a single dopant atom in a silicon FinFET. Nature Phys. 4, 656–661 (2008).

    CAS  Article  Google Scholar 

  21. Prati, E., Latempa, R. & Fanciulli, M. Microwave-assisted transport in a single-donor silicon quantum dot. Phys. Rev. B 80, 165331 (2009).

    Article  Google Scholar 

  22. Prati, E. et al. Adiabatic charge control in a single donor silicon quantum dot. Appl. Phys. Lett. 98, 053109 (2011).

    Article  Google Scholar 

  23. Mazzeo, G. et al. Charge dynamics of a single donor coupled to a few electrons quantum dot in silicon. Appl. Phys. Lett. 100, 213107 (2012).

    Article  Google Scholar 

  24. Thomas, G. A., Capizzi, M., DeRosa, F., Bhatt, R. N. & Rice, M. T. Optical study of interacting donors in semiconductors. Phys. Rev. B 23, 5472–5494 (1981).

    CAS  Article  Google Scholar 

  25. Sellier, H. et al. Transport spectroscopy of a single dopant in a gated silicon nanowire. Phys. Rev. Lett. 97, 206805 (2006).

    CAS  Article  Google Scholar 

  26. Beenakker, C. W. J. Theory of Coulomb-blockade oscillations in the conductance of a quantum dot. Phys. Rev. B 44, 1646–1656 (1991).

    CAS  Article  Google Scholar 

  27. Norton, P. Formation of the upper Hubbard band from negative-donor-ion states in silicon. Phys. Rev. Lett. 37, 164–168 (1976).

    CAS  Article  Google Scholar 

  28. Steele, G. A., Gotz, G. & Kouwenhoven, L. P. Tunable few-electron double quantum dots and Klein tunnelling in ultraclean carbon nanotubes. Nature Nanotech. 4, 363–367 (2009).

    CAS  Article  Google Scholar 

  29. Podor, B. et al. Wigner crystal and other insulating phases of two-dimensional electrons in high magnetic fields, Opto-Electron. Rev. 9, 195–202 (2001).

    CAS  Google Scholar 

  30. Moraru, D. et al. Atom devices based on single dopants in silicon nanostructures. Nano Res. Lett. 6, 479 (2011).

    Article  Google Scholar 

  31. Moraru, D., Kuzuya, Y., Mizuno, T., Tabe, M. & Mizuta, H. in Autumn JSAP symposium ‘Deterministic doping and single dopant devices for extended CMOS’, August 2011, Yamagata, Japan.

  32. Mizuta, H., Kuzuya, Y., Moraru, D., Mizuno, T. & Tabe, M. in Italy–Japan Workshop on Single Atom Control for Future Nanoelectronics, November 2011, Tokyo, Japan.

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This work was supported by SRC no. 1676.001, a Grant-in-Aid for Scientific Research (nos 22681020, 23226009 and 20241036) from MEXT, Japan, the PEST 2010-2012 Ministero Affari Esteri (MAE), Italy, and the Short-Term Mobility Program 2011, Consiglio Nazionale delle Ricerche (CNR), Italy.

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Authors and Affiliations



E.P. and F.G. carried out the measurements. M.H. and T.S. implanted the single donors. E.P., F.G. and G.F. analysed the data. E.P and T.S. designed the samples, the experiment and co-wrote the manuscript. All authors discussed the results and commented on the manuscript.

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Correspondence to Enrico Prati or Takahiro Shinada.

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The authors declare no competing financial interests.

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Prati, E., Hori, M., Guagliardo, F. et al. Anderson–Mott transition in arrays of a few dopant atoms in a silicon transistor. Nature Nanotech 7, 443–447 (2012).

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