Skip to main content

Thank you for visiting nature.com. 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.

  • Letter
  • Published:

An addressable quantum dot qubit with fault-tolerant control-fidelity

Abstract

Exciting progress towards spin-based quantum computing1,2 has recently been made with qubits realized using nitrogen-vacancy centres in diamond and phosphorus atoms in silicon3. For example, long coherence times were made possible by the presence of spin-free isotopes of carbon4 and silicon5. However, despite promising single-atom nanotechnologies6, there remain substantial challenges in coupling such qubits and addressing them individually. Conversely, lithographically defined quantum dots have an exchange coupling that can be precisely engineered1, but strong coupling to noise has severely limited their dephasing times and control fidelities. Here, we combine the best aspects of both spin qubit schemes and demonstrate a gate-addressable quantum dot qubit in isotopically engineered silicon with a control fidelity of 99.6%, obtained via Clifford-based randomized benchmarking and consistent with that required for fault-tolerant quantum computing7,8. This qubit has dephasing time T2* = 120 μs and coherence time T2 = 28 ms, both orders of magnitude larger than in other types of semiconductor qubit. By gate-voltage-tuning the electron g*-factor we can Stark shift the electron spin resonance frequency by more than 3,000 times the 2.4 kHz electron spin resonance linewidth, providing a direct route to large-scale arrays of addressable high-fidelity qubits that are compatible with existing manufacturing technologies.

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

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

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

Figure 1: Silicon quantum dot qubit with single electron transistor (SET) readout and on-chip microwave spin control.
Figure 2: Electron spin resonance (ESR) and Rabi oscillations.
Figure 3: Qubit coherence.
Figure 4: Control fidelity analysis via randomized benchmarking of Clifford gates.
Figure 5: Gate-voltage tunability of the qubit operation frequency and of the valley splitting.

Similar content being viewed by others

References

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

    Article  Google Scholar 

  2. DiVincenzo, D. P. The physical implementation of quantum computation. Fortschr. Phys. 48, 771–783 (2000).

    Article  Google Scholar 

  3. Awschalom, D. D., Bassett, L. C., Dzurak, A. S., Hu, E. L. & Petta, J. R. Quantum spintronics: engineering and manipulating atom-like spins in semiconductors. Science 339, 1174–1179 (2012).

    Google Scholar 

  4. Bar-Gill, N., Pham, L. M., Jarmola, A., Budker, D. & Walsworth, R. L. Solid-state electronic spin coherence time approaching one second. Nature Commun. 4, 1743 (2013).

    Article  CAS  Google Scholar 

  5. Tyryshkin, A. M. et al. Electron spin coherence exceeding seconds in high-purity silicon. Nature Mater 11, 143–147 (2012).

    Article  CAS  Google Scholar 

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

    Article  Google Scholar 

  7. Knill, E. Quantum computing with realistically noisy devices. Nature 434, 39–44 (2005).

    Article  CAS  Google Scholar 

  8. Fowler, A., Marlantoni, M., Martinis, J. M. & Cleland, A. N. Surface codes: towards practical large-scale quantum computation. Phys. Rev. A 86, 1–48 (2012).

    Google Scholar 

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

    Article  Google Scholar 

  10. Nowack, K. C. et al. Single-shot correlations and two-qubit gate of solid-state spins. Science 333, 1269–1272 (2011).

    Article  Google Scholar 

  11. Shulman, M. D. et al. Demonstration of entanglement of electrostatically coupled singlet–triplet qubits. Science 336, 202–205 (2012).

    Article  Google Scholar 

  12. Koppens, F. H. L., Nowack, K. C. & Vandersypen, L. M. K. Spin echo of a single electron spin in a quantum dot. Phys. Rev. Lett. 100, 236802 (2008).

    Article  CAS  Google Scholar 

  13. Bluhm, H., Foletti, S., Mahalu, D., Umansky, V. & Yacoby, A. Enhancing the coherence of a spin qubit by operating it as a feedback loop that controls its nuclear spin bath. Phys. Rev. Lett. 105, 216803 (2010).

    Article  Google Scholar 

  14. Maune, B. M. et al. Coherent singlet–triplet oscillations in a silicon-based double quantum dot. Nature 481, 344–347 (2012).

    Article  Google Scholar 

  15. Bluhm, H. et al. Dephasing time of GaAs electron–spin qubits coupled to a nuclear bath exceeding 200 µs. Nature Phys. 7, 109–113 (2011).

    Article  CAS  Google Scholar 

  16. Büch, H., Mahapatra, S., Rahman, R., Morello, A. & Simmons, M. Y. Spin readout and addressability of phosphorus-donor clusters in silicon. Nature Commun. 4, 2017 (2013).

    Article  Google Scholar 

  17. Nadj-Perge, S., Frolov, S. M., Bakkers, E. P. A. M. & Kouwenhoven, L. P. Spin–orbit qubit in a semiconductor nanowire. Nature 468, 1084–1087 (2010).

    Article  CAS  Google Scholar 

  18. Rahman, R. et al. Gate-induced g-factor control and dimensional transition for donors in multivalley semiconductors. Phys. Rev. B 80, 155301 (2009).

    Article  Google Scholar 

  19. Angus, S. J., Ferguson, A. J., Dzurak, A. S. & Clark, R. G. Gate-defined quantum dots in intrinsic silicon. Nano Lett. 7, 2051–2055 (2007).

    Article  Google Scholar 

  20. Fukatsu, S. et al. Effect of the Si/SiO2 interface on self-diffusion of Si in semiconductor-grade SiO2 . Appl. Phys. Lett. 83, 3897–3899 (2003).

    Article  Google Scholar 

  21. Pla, J. J. et al. A single-atom electron spin qubit in silicon. Nature 489, 541–545 (2012).

    Article  CAS  Google Scholar 

  22. Yang, C. H., Lim, W. H., Zwanenburg, F. A. & Dzurak, A. S. Dynamically controlled charge sensing of a few-electron silicon quantum dot. AIP Adv. 1, 042111 (2011).

    Article  Google Scholar 

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

    Article  Google Scholar 

  24. Koppens, F. H. L. et al. Driven coherent oscillations of a single electron spin in a quantum dot. Nature 442, 766–771 (2006).

    Article  Google Scholar 

  25. Knill, E. et al. Randomized benchmarking of quantum gates. Phys. Rev. A 77, 012307 (2008).

    Article  Google Scholar 

  26. Yang, C. H. et al. Spin-valley lifetimes in a silicon quantum dot with tunable valley splitting. Nature Commun. 4, 2069 (2013).

    Article  CAS  Google Scholar 

  27. Hao, X., Ruskov, R., Xiao, M., Tahan, C. & Jian, H. W. Electron spin resonance and spin-valley physics in a silicon double quantum dot. Nature Commun. 5, 3860 (2014).

    Article  CAS  Google Scholar 

  28. Bradbury, F. R. et al. Stark tuning of donor electron spins in silicon. Phys. Rev. Lett. 97, 176404 (2006).

    Article  CAS  Google Scholar 

  29. Muhonen, J. T. et al. Storing quantum information for 30 seconds in a nanoelectronic device. Preprint at http://arXiv.org/abs/1402.7140 (2014).

  30. Kalra, R., Laucht, A., Hill, C. D. & Morello, A. Robust two-qubit gates for donors in silicon controlled by hyperfine interactions. Phys. Rev. X 4, 021044 (2014).

    Google Scholar 

Download references

Acknowledgements

The authors thank D. J. Reilly and J. R. Petta for discussions. The authors acknowledge support from the Australian Research Council (CE11E0096), the US Army Research Office (W911NF-13-1-0024) and the NSW Node of the Australian National Fabrication Facility. M.V. acknowledges support from the Netherlands Organization for Scientific Research (NWO) through a Rubicon Grant. The work at Keio has been supported in part by FIRST, the Core-to-Core Program by JSPS, and the Grant-in-Aid for Scientific Research and Project for Developing Innovation Systems by MEXT.

Author information

Authors and Affiliations

Authors

Contributions

M.V., J.C.C.H., C.H.Y., A.W.L., B.R., J.P.D. and J.T.M. performed the experiments. M.V. and F.E.H. fabricated the devices. K.M.I. prepared and supplied the 28Si epilayer wafer. M.V., C.H.Y., A.M. and A.S.D. designed the experiments and analysed the results. M.V. and A.S.D. wrote the manuscript, with input from all authors.

Corresponding authors

Correspondence to M. Veldhorst or A. S. Dzurak.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary Information (PDF 752 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Veldhorst, M., Hwang, J., Yang, C. et al. An addressable quantum dot qubit with fault-tolerant control-fidelity. Nature Nanotech 9, 981–985 (2014). https://doi.org/10.1038/nnano.2014.216

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nnano.2014.216

This article is cited by

Search

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