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.

  • Article
  • Published:

Quantum error correction and universal gate set operation on a binomial bosonic logical qubit

Abstract

Logical qubit encoding and quantum error correction (QEC) protocols have been experimentally demonstrated in various physical systems with multiple physical qubits, generally without reaching the break-even point, at which the lifetime of the quantum information exceeds that of the single best physical qubit within the logical qubit. Logical operations are challenging, owing to the necessary non-local operations at the physical level, making bosonic logical qubits that rely on higher Fock states of a single oscillator attractive, given their hardware efficiency. QEC that reaches the break-even point and single logical-qubit operations have been demonstrated using the bosonic cat code. Here, we experimentally demonstrate repetitive QEC approaching the break-even point of a single logical qubit encoded in a hybrid system consisting of a superconducting circuit and a bosonic cavity using a binomial bosonic code. This is achieved while simultaneously maintaining full control of the single logical qubit, including encoding, decoding and a high-fidelity universal quantum gate set with 97% average process fidelity. The corrected logical qubit has a lifetime 2.8 times longer than that of its uncorrected counterpart. We also perform a Ramsey experiment on the corrected logical qubit, reporting coherence twice as long as for the uncorrected case.

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

Access options

Buy this article

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

Fig. 1: Schematic of the experiments on binomial quantum code.
Fig. 2: Protocol of the repetitive QEC and process tomography.
Fig. 3: QEC performance.
Fig. 4: Gate operations on the logical qubit and Ramsey interferometry on the QEC-protected logical qubit.

Similar content being viewed by others

Data availability

The data that support the plots within this paper and other findings of this study are available from the corresponding authors upon request.

References

  1. Nielsen, M. A. & Chuang, I. L. Quantum Computation And Quantum Information (Cambridge University Press, Cambridge, 2000).

  2. Shor, P. W. Scheme for reducing decoherence in quantum computer memory. Phys. Rev. A 52, 2493–2496 (1995).

    Article  ADS  Google Scholar 

  3. Steane, A. Multiple particle interference and quantum error correction. Proc. R. Soc. Lond. A 452, 2551–2577 (1996).

    Article  ADS  MathSciNet  Google Scholar 

  4. Gottesman, D. An introduction to quantum error correction and fault-tolerant quantum computation. Proc. Symp. Appl. Math. 68, 13–58 (2010).

    Article  MathSciNet  Google Scholar 

  5. Fowler, A. G., Mariantoni, M., Martinis, J. M. & Cleland, A. N. Surface codes: towards practical large-scale quantum computation. Phys. Rev. A 86, 032324 (2012).

    Article  ADS  Google Scholar 

  6. Devoret, M. H. & Schoelkopf, R. J. Superconducting circuits for quantum information: an outlook. Science 339, 1169–1174 (2013).

    Article  ADS  Google Scholar 

  7. Cory, D. G. et al. Experimental quantum error correction. Phys. Rev. Lett. 81, 2152–2155 (1998).

    Article  ADS  Google Scholar 

  8. Chiaverini, J. et al. Realization of quantum error correction. Nature 432, 602–605 (2004).

    Article  ADS  Google Scholar 

  9. Schindler, P. et al. Experimental repetitive quantum error correction. Science 332, 1059–1061 (2011).

    Article  ADS  Google Scholar 

  10. Reed, M. D. et al. Realization of three-qubit quantum error correction with superconducting circuits. Nature 482, 382–385 (2012).

    Article  ADS  Google Scholar 

  11. Waldherr, G. et al. Quantum error correction in a solid-state hybrid spin register. Nature 506, 204–207 (2014).

    Article  ADS  Google Scholar 

  12. Taminiau, T. H., Cramer, J., van der Sar, T., Dobrovitski, V. V. & Hanson, R. Universal control and error correction in multi-qubit spin registers in diamond. Nat. Nanotechnol. 9, 171–176 (2014).

    Article  ADS  Google Scholar 

  13. Nigg, D. et al. Quantum computations on a topologically encoded qubit. Science 345, 302–305 (2014).

    Article  ADS  MathSciNet  Google Scholar 

  14. Kelly, J. et al. State preservation by repetitive error detection in a superconducting quantum circuit. Nature 519, 66–69 (2015).

    Article  ADS  Google Scholar 

  15. Corcoles, A. D. et al. Demonstration of a quantum error detection code using a square lattice of four superconducting qubits. Nat. Commun. 6, 6979 (2015).

    Article  Google Scholar 

  16. Riste, D. et al. Detecting bit-flip errors in a logical qubit using stabilizer measurements. Nat. Commun. 6, 6983 (2015).

    Article  Google Scholar 

  17. Cramer, J. et al. Repeated quantum error correction on a continuously encoded qubit by real-time feedback. Nat. Commun. 7, 11526 (2016).

    Article  ADS  Google Scholar 

  18. Gottesman, D., Kitaev, A. & Preskill, J. Encoding a qubit in an oscillator. Phys. Rev. A 64, 012310 (2001).

    Article  ADS  Google Scholar 

  19. Leghtas, Z. et al. Hardware-efficient autonomous quantum memory protection. Phys. Rev. Lett. 111, 120501 (2013).

    Article  ADS  Google Scholar 

  20. Mirrahimi, M. et al. Dynamically protected cat-qubits: a new paradigm for universal quantum computation. New J. Phys. 16, 045014 (2014).

    Article  ADS  Google Scholar 

  21. Vlastakis, B. et al. Deterministically encoding quantum information using 100-photon Schrodinger cat states. Science 342, 607–610 (2013).

    Article  ADS  MathSciNet  Google Scholar 

  22. Sun, L. et al. Tracking photon jumps with repeated quantum non-demolition parity measurements. Nature 511, 444–448 (2014).

    Article  ADS  Google Scholar 

  23. Leghtas, Z. et al. Confining the state of light to a quantum manifold by engineered two-photon loss. Science 347, 853–857 (2015).

    Article  ADS  Google Scholar 

  24. Ofek, N. et al. Extending the lifetime of a quantum bit with error correction in superconducting circuits. Nature 536, 441–445 (2016).

    Article  ADS  Google Scholar 

  25. Wang, C. et al. A Schrödinger cat living in two boxes. Science 352, 1087–1091 (2016).

    Article  ADS  MathSciNet  Google Scholar 

  26. Heeres, R. W. et al. Implementing a universal gate set on a logical qubit encoded in an oscillator. Nat. Commun. 8, 94 (2017).

    Article  ADS  Google Scholar 

  27. Chou, K. S. et al. Deterministic teleportation of a quantum gate between two logical qubits. Nature 561, 368–373 (2018).

    Article  Google Scholar 

  28. Rosenblum, S. et al. A CNOT gate between multi-photon qubits encoded in two cavities. Nat. Commun. 9, 652 (2018).

    Article  ADS  Google Scholar 

  29. Albert, V. V. et al. Performance and structure of single-mode bosonic codes. Phys. Rev. A 97, 032346 (2018).

    Article  ADS  Google Scholar 

  30. Flühmann, C. et al. Encoding a qubit in a trapped-ion mechanical oscillator. Preprint at https://arxiv.org/abs/1807.01033 (2018).

  31. Krastanov, S. et al. Universal control of an oscillator with dispersive coupling to a qubit. Phys. Rev. A 92, 040303 (2015).

    Article  ADS  Google Scholar 

  32. Michael, M. H. et al. New class of quantum error-correcting codes for a bosonic mode. Phys. Rev. X 6, 031006 (2016).

    Google Scholar 

  33. Li, L. et al. Cat codes with optimal decoherence suppression for a lossy bosonic channel. Phys. Rev. Lett. 119, 030502 (2017).

    Article  ADS  Google Scholar 

  34. Rosenblum, S. et al. Fault-tolerant detection of a quantum error. Science 361, 266–270 (2018).

    Article  ADS  MathSciNet  Google Scholar 

  35. Zhou, S., Zhang, M., Preskill, J. & Jiang, L. Achieving the Heisenberg limit in quantum metrology using quantum error correction. Nat. Commun. 9, 78 (2018).

    Article  ADS  Google Scholar 

  36. Kurizki, G. et al. Quantum technologies with hybrid systems. Proc. Natl Acad. Sci. USA 112, 3866–3873 (2015).

    Article  ADS  Google Scholar 

  37. Wallraff, A. et al. Strong coupling of a single photon to a superconducting qubit using circuit quantum electrodynamics. Nature 431, 162–167 (2004).

    Article  ADS  Google Scholar 

  38. Paik, H. et al. Observation of high coherence in Josephson junction qubits measured in a three-dimensional circuit QED architecture. Phys. Rev. Lett. 107, 240501 (2011).

    Article  ADS  Google Scholar 

  39. Liu, K. et al. A twofold quantum delayed-choice experiment in a superconducting circuit. Sci. Adv. 3, e1603159 (2017).

    Article  ADS  Google Scholar 

  40. Kirchmair, G. et al. Observation of quantum state collapse and revival due to the single-photon Kerr effect. Nature 495, 205–209 (2013).

    Article  ADS  Google Scholar 

  41. Khaneja, N., Reiss, T., Kehlet, C., Schulte-Herbriiggen, T. & Glaser, S. J. Optimal control of coupled spin dynamics: design of NMR pulse sequences by gradient ascent algorithms. J. Magn. Reson. 172, 296–305 (2005).

    Article  ADS  Google Scholar 

  42. De Fouquieres, P., Schirmer, S., Glaser, S. & Kuprov, I. Second order gradient ascent pulse engineering. J. Magn. Reson. 212, 412–417 (2011).

    Article  ADS  Google Scholar 

  43. Barends, R. et al. Superconducting quantum circuits at the surface code threshold for fault tolerance. Nature 508, 500–503 (2014).

    Article  ADS  Google Scholar 

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

    Article  ADS  Google Scholar 

  45. Ryan, C. A., Laforest, M. & Laflamme, R. Randomized benchmarking of single- and multi-qubit control in liquid-state NMR quantum information processing. New J. Phys. 11, 013034 (2009).

    Article  ADS  Google Scholar 

  46. Magesan, E. et al. Efficient measurement of quantum gate error by interleaved randomized benchmarking. Phys. Rev. Lett. 109, 080505 (2012).

    Article  ADS  Google Scholar 

  47. Carignan-Dugas, A., Wallman, J. J. & Emerson, J. Characterizing universal gate sets via dihedral benchmarking. Phys. Rev. A 92, 060302 (2015).

    Article  ADS  Google Scholar 

  48. Cross, A. W., Magesan, E., Bishop, L. S., Smolin, J. A. & Gambetta, J. M. Scalable randomised benchmarking of non-Clifford gates. npj Quantum Inf. 2, 16012 (2016).

    Article  ADS  Google Scholar 

  49. Harper, R. & Flammia, S. T. Estimating the fidelity of T gates using standard interleaved randomized benchmarking. Quantum Sci. Technol. 2, 015008 (2017).

    Article  ADS  Google Scholar 

  50. Axline, C. et al. An architecture for integrating planar and 3D cQED devices. Appl. Phys. Lett. 109, 042601 (2016).

    Article  ADS  Google Scholar 

  51. Chu, Y. et al. Quantum acoustics with superconducting qubits. Science 358, 199–202 (2017).

    Article  ADS  MathSciNet  Google Scholar 

  52. Tabuchi, Y. et al. Coherent coupling between a ferromagnetic magnon and a superconducting qubit. Science 349, 405–408 (2015).

    Article  ADS  MathSciNet  Google Scholar 

  53. Kaufman, A. M., Lester, B. J. & Regal, C. A. Cooling a single atom in an optical tweezer to its quantum ground state. Phys. Rev. X 2, 041014 (2012).

    Google Scholar 

  54. Um, M. et al. Phonon arithmetic in a trapped ion system. Nat. Commun. 7, 11410 (2016).

    Article  ADS  Google Scholar 

Download references

Acknowledgements

We thank N. Ofek and Y. Liu for suggestions on FPGA programming, and L. Jiang, L. Li and R. Schoelkopf for discussions. L.S. acknowledges support from the National Key Research and Development Program of China grant number 2017YFA0304303 and National Natural Science Foundation of China grant number 11474177. S.M.G. acknowledges grants from ARO W911NF1410011 and NSF DMR-1609326. L.S. also thanks R. Vijay and his group for help on the parametric amplifier measurements.

Author information

Authors and Affiliations

Authors

Contributions

L.H. and L.S. developed the FPGA logic. L.H. and Y.M. performed the experiment and analysed the data with the assistance of W.C., X.M., Y.X. and W.W. L.S. directed the experiment. L.M.D., C.L.Z. and L.S. proposed the experiment. C.-L.Z., Y.W., S.M.G. and L.-M.D. provided theoretical support. W.C. fabricated the JPA. L.H. and X.M. fabricated the devices with the assistance of Y.X., H.W. and Y.P.S. C.-L.Z., S.M.G. and L.S. wrote the manuscript with feedback from all authors.

Corresponding authors

Correspondence to C.-L. Zou or L. Sun.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Journal peer review information: Nature Physics thanks P. van Loock and the other anonymous reviewer(s) for their contribution to the peer review of this work.

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Supplementary Information

Supplementary Figures and Methods.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Hu, L., Ma, Y., Cai, W. et al. Quantum error correction and universal gate set operation on a binomial bosonic logical qubit. Nat. Phys. 15, 503–508 (2019). https://doi.org/10.1038/s41567-018-0414-3

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41567-018-0414-3

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