Letter | Published:

Single-qubit quantum memory exceeding ten-minute coherence time

Abstract

A long-time quantum memory capable of storing and measuring quantum information at the single-qubit level is an essential ingredient for practical quantum computation and communication1,2. Currently, the coherence time of a single qubit is limited to less than 1 min, as demonstrated in trapped ion systems3,4,5, although much longer coherence times have been reported in ensembles of trapped ions6,7 and nuclear spins of ionized donors8,9. Here, we report the observation of a coherence time of over 10 min for a single qubit in a 171Yb+ ion sympathetically cooled by a 138Ba+ ion in the same Paul trap, which eliminates the problem of qubit-detection inefficiency from heating of the qubit ion10,11. We also apply a few thousand dynamical decoupling pulses to suppress ambient noise from magnetic-field fluctuations and phase noise from the local oscillator8,9,12,13,14,15,16. The long-time quantum memory of the single trapped ion qubit would be the essential component of scalable quantum computers1,17,18, quantum networks2,19,20 and quantum money21,22.

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A correction to this article is available online at https://doi.org/10.1038/s41566-017-0052-9.

Change history

  • 12 January 2018

    In the version of this Letter originally published, in Fig. 2c legend, the entry ‘LO phase noise’ should not have been included. This has now been corrected in the online versions.

References

  1. 1.

    Ladd, T. D. et al. Quantum computers. Nature 464, 45–53 (2010).

  2. 2.

    Duan, L.-M. & Monroe, C. Quantum networks with trapped ions. Rev. Mod. Phys. 82, 1209–1224 (2012).

  3. 3.

    Langer, C. et al. Long-lived qubit memory using atomic ions. Phys. Rev. Lett. 95, 060502 (2005).

  4. 4.

    Häffner, H. et al. Robust entanglement. Appl. Phys. B 81, 151–153 (2005).

  5. 5.

    Harty, T. et al. High-fidelity preparation, gates, memory, and readout of a trapped-ion quantum bit. Phys. Rev. Lett. 113, 220501 (2014).

  6. 6.

    Bollinger, J., Heizen, D., Itano, W., Gilbert, S. & Wineland, D. A 303-MHz frequency standard based on trapped Be+ ions. IEEE Trans. Instrum. Meas. 40, 126–128 (1991).

  7. 7.

    Fisk, P. et al. Very high Q microwave spectroscopy on trapped 171Yb+ ions: application as a frequency standard. IEEE Trans. Instrum. Meas. 44, 113–116 (1995).

  8. 8.

    Saeedi, K. et al. Room-temperature quantum bit storage exceeding 39 minutes using ionized donors in silicon-28. Science 342, 830–833 (2013).

  9. 9.

    Zhong, M. et al. Optically addressable nuclear spins in a solid with a six-hour coherence time. Nature 517, 177–180 (2015).

  10. 10.

    Epstein, R. J. et al. Simplified motional heating rate measurements of trapped ions. Phys. Rev. A 76, 033411 (2007).

  11. 11.

    Wesenberg, J. et al. Fluorescence during Doppler cooling of a single trapped atom. Phys. Rev. A 76, 053416 (2007).

  12. 12.

    Khodjasteh, K. et al. Designing a practical high-fidelity long-time quantum memory. Nat. Commun. 4, 2045 (2013).

  13. 13.

    Biercuk, M. J. et al. Optimized dynamical decoupling in a model quantum memory. Nature 458, 996–1000 (2009).

  14. 14.

    Kotler, S., Akerman, N., Glickman, Y. & Ozeri, R. Nonlinear single-spin spectrum analyzer. Phys. Rev. Lett. 110, 110503 (2013).

  15. 15.

    Souza, A. M., Álvarez, G. A. & Suter, D. Robust dynamical decoupling for quantum computing and quantum memory. Phys. Rev. Lett. 106, 240501 (2011).

  16. 16.

    Haeberlen, U. High Resolution NMR in Solids Selective Averaging (Elsevier, 1976).

  17. 17.

    Kielpinski, D., Monroe, C. & Wineland, D. J. Architecture for a large-scale ion-trap quantum computer. Nature 417, 709–711 (2002).

  18. 18.

    Lekitsch, B. et al. Blueprint for a microwave trapped ion quantum computer. Sci. Adv. 3, e1601540 (2017).

  19. 19.

    Monroe, C. & Kim, J. Scaling the ion trap quantum processor. Science 339, 1164–1169 (2013).

  20. 20.

    Nickerson, N. H., Fitzsimons, J. F. & Benjamin, S. C. Freely scalable quantum technologies using cells of 5-to-50 qubits with very lossy and noisy photonic links. Phys. Rev. X 4, 041041 (2014).

  21. 21.

    Wiesner, S. Conjugate coding. ACM SIGACT News 15, 78–88 (1983).

  22. 22.

    Pastawski, F., Yao, N. Y., Jiang, L., Lukin, M. D. & Cirac, J. I. Unforgeable noise-tolerant quantum tokens. Proc. Natl Acad. Sci. USA 109, 16079–16082 (2012).

  23. 23.

    Hite, D. A. et al. 100-fold reduction of electric-field noise in an ion trap cleaned with in situ argon-ion-beam bombardment. Phys. Rev. Lett. 109, 103001 (2012).

  24. 24.

    Deslauriers, L. et al. Scaling and suppression of anomalous heating in ion traps. Phys. Rev. Lett. 97, 103007 (2006).

  25. 25.

    Nielsen, M. A. & Chuang, I. L. Quantum Computation and Quantum Information (Cambridge Univ. Press, 2010).

  26. 26.

    Home, J. P. et al. Complete methods set for scalable ion trap quantum information processing. Science 325, 1227–1230 (2009).

  27. 27.

    Hanneke, D. et al. Realization of a programmable two-qubit quantum processor. Nat. Phys. 6, 13–16 (2010).

  28. 28.

    Duan, L. M., Blinov, B. B., Moehring, D. L. & Monroe, C. Scalable trapped ion quantum computation with a probabilistic ion-photon mapping. Quantum Inf. Comput. 4, 165–173 (2004).

  29. 29.

    Blinov, B., Moehring, D., Duan, L.-M. & Monroe, C. Observation of entanglement between a single trapped atom and a single photon. Nature 428, 153–157 (2004).

  30. 30.

    Moehring, D. L. et al. Entanglement of single atom quantum bits at a distance. Nature 449, 68–71 (2007).

  31. 31.

    Kurz, C. et al. Experimental protocol for high-fidelity heralded photon-to-atom quantum state transfer. Nat. Commun. 5, 5527 (2014).

  32. 32.

    Ball, H., Oliver, W. D. & Biercuk, M. J. The role of master clock stability in quantum information processing. Nat. Quantum Inf. 2, 16033 (2016).

  33. 33.

    Bylander, J. et al. Noise spectroscopy through dynamical decoupling with a superconducting flux qubit. Nat. Phys. 7, 565–570 (2011).

  34. 34.

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

  35. 35.

    Kielpinski, D., Kafri, D., Woolley, M. J., Milburn, G. J. & Taylor, J. M. Quantum interface between an electrical circuit and a single atom. Phys. Rev. Lett. 108, 130504 (2012).

  36. 36.

    Daniilidis, N., Gorman, D. J., Tian, L. & Hffner, H. Quantum information processing with trapped electrons and superconducting electronics. New J. Phys. 251, 073017 (2013).

  37. 37.

    Ozeri, R. et al. Hyperfine coherence in the presence of spontaneous photon scattering. Phys. Rev. Lett. 95, 030403 (2005).

  38. 38.

    Uys, H. et al. Decoherence due to elastic Rayleigh scattering. Phys. Rev. Lett. 105, 200401 (2010).

  39. 39.

    Campbell, W. et al. Ultrafast gates for single atomic qubits. Phys. Rev. Lett. 105, 090502 (2010).

  40. 40.

    Fisk, P. T., Sellars, M. J., Lawn, M. A. & Coles, G. Accurate measurement of the 12.6 GHz clock transition in trapped 171Yb+ ions. IEEE Trans. Ultrason. Ferroelectr. Freq. Control 44, 344–354 (1997).

  41. 41.

    Uhrig, G. S. Exact results on dynamical decoupling by π pulses in quantum information processes. New J. Phys. 10, 083024 (2008).

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Acknowledgements

This work was supported by the National Key Research and Development Program of China under grant 2016YFA0301900 (no. 2016YFA0301901) and the National Natural Science Foundation of China grants 11374178, 11504197 and 11574002.

Author information

Y.W. and D.Y. developed the experimental system. Y.W., with the participation of M.U. and D.Y., collected and analysed the data. J.Z. and S.A. provided technical support. M.L., J.-N.Z., L.-M.D. and D.Y. provided theoretical support. K.K. supervised the project. All authors contributed to writing the manuscript.

Competing interests

The authors declare no competing financial interests.

Correspondence to Dahyun Yum or Kihwan Kim.

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Further reading

Fig. 1: Experimental set-up.
Fig. 2: Measurement of the noise spectrum of the system.
Fig. 3: KDD xy sequence and gate fidelity.
Fig. 4: Coherence time measurement and quantum process tomography.