On-demand single-electron transfer between distant quantum dots

Abstract

Single-electron circuits of the future, consisting of a network of quantum dots, will require a mechanism to transport electrons from one functional part of the circuit to another. For example, in a quantum computer1 decoherence and circuit complexity can be reduced by separating quantum bit (qubit) manipulation from measurement and by providing a means of transporting electrons between the corresponding parts of the circuit2. Highly controlled tunnelling between neighbouring dots has been demonstrated3,4, and our ability to manipulate electrons in single- and double-dot systems is improving rapidly5,6,7,8. For distances greater than a few hundred nanometres, neither free propagation nor tunnelling is viable while maintaining confinement of single electrons. Here we show how a single electron may be captured in a surface acoustic wave minimum and transferred from one quantum dot to a second, unoccupied, dot along a long, empty channel. The transfer direction may be reversed and the same electron moved back and forth more than sixty times—a cumulative distance of 0.25 mm—without error. Such on-chip transfer extends communication between quantum dots to a range that may allow the integration of discrete quantum information processing components and devices.

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Figure 1: Device, initialization and single-electron transfer.
Figure 2: Single-electron transfer reliability.
Figure 3: Dependence of LQD depopulation on SAW power and pulse width.
Figure 4: Backscattering of electrons in the RQD due to SAW(L).

References

  1. 1

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

  2. 2

    Barnes, C. H. W., Shilton, J. M. & Robinson, A. M. Quantum computation using electrons trapped by surface acoustic waves. Phys. Rev. B 62, 8410–8419 (2000)

  3. 3

    Petta, J. R. et al. Coherent manipulation of coupled electron spins in semiconductor quantum dots. Science 309, 2180–2184 (2005)

  4. 4

    Pioro-Ladrière, M. et al. Electrically driven single-electron spin resonance in a slanting Zeeman field. Nature Phys. 4, 776–779 (2008)

  5. 5

    Elzerman, J. M. et al. Single-shot read-out of an individual electron spin in a quantum dot. Nature 430, 431–435 (2004)

  6. 6

    Hanson, R. et al. Single-shot readout of electron spin states in a quantum dot using spin-dependent tunnel rates. Phys. Rev. Lett. 94, 196802 (2005)

  7. 7

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

  8. 8

    Hanson, R., Kouwenhoven, L. P., Petta, J. R., Tarucha, S. & Vandersypen, L. M. K. Spins in few-electron quantum dots. Rev. Mod. Phys. 79, 1217–1265 (2007)

  9. 9

    Field, M. et al. Measurements of Coulomb blockade with a noninvasive voltage probe. Phys. Rev. Lett. 70, 1311–1314 (1993)

  10. 10

    Kataoka, M., Barnes, C. H. W., Beere, H. E., Ritchie, D. A. & Pepper, M. Experimental investigation of the surface acoustic wave electron capture mechanism. Phys. Rev. B 74, 085302 (2006)

  11. 11

    Rahman, S., Kataoka, M., Barnes, C. H. W. & Langtangen, H. P. Numerical investigation of a piezoelectric surface acoustic wave interaction with a one-dimensional channel. Phys. Rev. B 74, 035308 (2006)

  12. 12

    Kataoka, M. et al. Single-electron population and depopulation of an isolated quantum dot using a surface-acoustic-wave pulse. Phys. Rev. Lett. 98, 046801 (2007)

  13. 13

    Taubert, D. et al. Relaxation of hot electrons in a degenerate two-dimensional electron system: transition to one-dimensional scattering. Phys. Rev. B 83, 235404 (2011)

  14. 14

    Fujisawa, T. et al. Spontaneous emission spectrum in double quantum dot devices. Science 282, 932–935 (1998)

  15. 15

    Gell, J. R. et al. Surface-acoustic-wave-driven luminescence from a lateral p–n junction. Appl. Phys. Lett. 89, 243505 (2006)

  16. 16

    Stotz, J. A. H., Hey, R., Santos, P. V. & Ploog, K. H. Coherent spin transport through dynamic quantum dots. Nature Mater. 4, 585–588 (2005)

  17. 17

    Kataoka, M. et al. Coherent time evolution of a single-electron wave function. Phys. Rev. Lett. 102, 156801 (2009)

  18. 18

    Morgan, D. Surface Acoustic Wave Design 9–18 (Academic, 2007)

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Acknowledgements

The authors acknowledge funding from the UK EPSRC, Toshiba Research Europe Limited and QIPIRC.

Author information

R.P.G.M., M.K., C.J.B.F. and C.H.W.B. designed the experiment; I.F. and D.A.R. provided wafers; D.A. and G.A.C.J. performed electron-beam lithography; R.P.G.M. processed samples and analysed data; R.P.G.M. and M.K. performed experiments; R.P.G.M., C.J.B.F. and M.K. wrote the paper.

Correspondence to C. J. B. Ford.

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The authors declare no competing financial interests.

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McNeil, R., Kataoka, M., Ford, C. et al. On-demand single-electron transfer between distant quantum dots. Nature 477, 439–442 (2011). https://doi.org/10.1038/nature10444

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