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.

# A quantum memory intrinsic to single nitrogen–vacancy centres in diamond

## Abstract

A quantum memory, composed of a long-lived qubit coupled to each processing qubit, is important to building a scalable platform for quantum information science. These two qubits should be connected by a fast and high-fidelity operation to store and retrieve coherent quantum states. Here, we demonstrate a room-temperature quantum memory based on the spin of the nitrogen nucleus intrinsic to each nitrogen–vacancy (NV) centre in diamond. We perform coherent storage of a single NV centre electronic spin in a single nitrogen nuclear spin using Landau–Zener transitions across a hyperfine-mediated avoided level crossing. By working outside the asymptotic regime, we demonstrate coherent state transfer in as little as 120 ns with total storage fidelity of 88±6%. This work demonstrates the use of a quantum memory that is compatible with scaling as the nitrogen nucleus is deterministically present in each NV centre defect.

This is a preview of subscription content

## Access options

\$32.00

All prices are NET prices.

## References

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

2. Simon, C. et al. Quantum memories. Eur. Phys. J. D 58, 1–22 (2010).

3. Balasubramanian, B. et al. Ultralong spin coherence time in isotopically engineered diamond. Nature Mater. 8, 383–387 (2009).

4. Fuchs, G. D., Dobrovitski, V. V., Toyli, D. M., Heremans, F. J. & Awschalom, D. D. Gigahertz dynamics of a strongly driven single quantum spin. Science 326, 1520–1522 (2009).

5. Togan, E. et al. Quantum entanglement between an optical photon and a solid-state spin qubit. Nature 466, 730–735 (2010).

6. Buckley, B. B., Fuchs, G. D., Bassett, L. C. & Awschalom, D. D. Spin-light coherence for single-spin measurement and control in diamond. Science 330, 1212–1215 (2010).

7. Jelezko, F., Gaebel, T., Popa, I., Gruber, A. & Wrachtrup, J. Observation of coherent oscillations in a single electron spin. Phys. Rev. Lett. 92, 076401 (2004).

8. Jelezko, F., Gaebel, T., Popa, I., Domhan, M., Gruber, A. & Wrachtrup, J. Observation of coherent oscillation of a single nuclear spin and realization of a two-qubit conditional quantum gate. Phys. Rev. Lett. 93, 130501 (2004).

9. Gaebel, T. et al. Room-temperature coherent coupling of single spins in diamond. Nature Phys. 2, 408–413 (2006).

10. Hanson, R., Mendoza, F. M., Epstein, R. J. & Awschalom, D. D. Polarization and readout of coupled single spins in diamond. Phys. Rev. Lett. 97, 087601 (2006).

11. Childress, L. et al. Coherent dynamics of coupled electron and nuclear spin qubits in diamond. Science 314, 281–285 (2006).

12. Smeltzer, B., McIntyre, J. & Childress, L. Robust control of individual nuclear spins in diamond. Phys. Rev. A 80, 050302(R) (2009).

13. Neumann, P. et al. Single-shot readout of a single nuclear spin. Science 329, 542–544 (2010).

14. Dutt, M. V. G. et al. Quantum register based on individual electronic and nuclear spin qubits in diamond. Science 316, 1312–1316 (2007).

15. Toyli, D. M., Weis, C. D., Fuchs, G. D., Schenkel, T. & Awschalom, D. D. Chip-scale nanofabrication of single spins and spin arrays in diamond. Nano Lett. 10, 3168–3172 (2010).

16. Landau, L. D. Zur Theorie der Energieübertragung II. Phys. Z. Sow. 2, 46–51 (1932).

17. Zener, C. Non-adiabatic crossing of energy levels. Proc. R. Soc. Lond. A 137, 696–702 (1932).

18. Stückelberg, E. C. G. Theorie der unelastichen Stösse zwischen Atomen. Helv. Phys. Acta 5, 369–422 (1932).

19. Majorana, E. Atomi orientati in campo magnetico variabile. Nuovo Cimento. 9, 43–50 (1932).

20. Petta, J. R., Lu, H. & Gossard, A. C. A coherent beam splitter for electronic spin states. Science 327, 669–672 (2010).

21. Oliver, W. D. et al. Mach–Zehnder interferometry in a strongly driven superconducting qubit. Science 310, 1653–1657 (2005).

22. Shevchenko, S. N., Ashhab, S. & Nori, F. Landau–Zener–Stückelberg interferometry. Phys. Rep. 492, 1–30 (2010).

23. Felton, S. et al. Hyperfine interaction in the ground state of the negatively charged nitrogen vacancy center in diamond. Phys. Rev. B 79, 075203 (2009).

24. Vitanov, N. V. & Garraway, B. M. Landau–Zener model: Effects of finite coupling duration. Phys. Rev. A 53, 4288–4304 (1996).

25. Manson, N. B., Harrison, J. P. & Sellars, M. J. Nitrogen–vacancy center in diamond: Model of the electronic structure and associated dynamics. Phys. Rev. B 74, 104303 (2006).

26. Manson, N. B., Rogers, L., Doherty, M. & Hollenberg, L. Optically induced spin polarization of the NV-centre in diamond: role of electron-vibration interaction, http://arxiv.org/abs/1011.2840v1 (2010).

27. Fuchs, G. D. et al. Excited-state spectroscopy using single spin manipulation in diamond. Phys. Rev. Lett. 101, 117601 (2008).

28. Jaques, V. et al. Dynamic polarization of single nuclear spins by optical pumping of nitrogen–vacancy color centers in diamond at room temperature. Phys. Rev. Lett. 102, 057403 (2009).

29. Steiner, M., Neumann, P., Beck, J., Jelezko, F. & Wrachtrup, J. Universal enhancement of the optical readout fidelity of single electron spins at nitrogen–vacancy centers in diamond. Phys. Rev. B 81, 035205 (2010).

30. Hanson, R., Gywat, O. & Awschalom, D. D. Room-temperature manipulation and decoherence of a single spin in diamond. Phys. Rev. B 74, 161203(R) (2006).

31. Haynes, W. M. & Lide, D. R. (eds) Handbook of Chemistry and Physics (CRC, 2010).

32. de Lange, G., Wang, Z. H., Risté, D., Dobrovitski, V. V. & Hanson, R. Universal dynamical decoupling of a single solid-state spin from a spin bath. Science 330, 60–63 (2010).

## Acknowledgements

The authors thank H. Ribeiro for helpful comments on the theory. We gratefully acknowledge support from the AFOSR, ARO and DARPA. G.B. acknowledges funding from DFG within SFB767, from the Konstanz Center for Applied Photonics (CAP), and from the Research Initiative UltraQuantum.

## Author information

Authors

### Contributions

The experiment was designed and analysed by G.D.F., G.B., P.V.K. and D.D.A. Measurements were made by G.D.F. and P.V.K. Samples were designed and fabricated by G.D.F. All authors contributed to writing the paper.

### Corresponding author

Correspondence to D. D. Awschalom.

## Ethics declarations

### Competing interests

The authors declare no competing financial interests.

## Supplementary information

### Supplementary Information

Supplementary Information (PDF 781 kb)

## Rights and permissions

Reprints and Permissions

Fuchs, G., Burkard, G., Klimov, P. et al. A quantum memory intrinsic to single nitrogen–vacancy centres in diamond. Nature Phys 7, 789–793 (2011). https://doi.org/10.1038/nphys2026

• Accepted:

• Published:

• Issue Date:

• DOI: https://doi.org/10.1038/nphys2026

• ### Excited-state spin-resonance spectroscopy of V$${}_{{{{{{{{\rm{B}}}}}}}}}^{-}$$ defect centers in hexagonal boron nitride

• Nikhil Mathur
• Arunabh Mukherjee
• Gregory D. Fuchs

Nature Communications (2022)

• ### Dynamical transition in a nonlinear two-level system driven by a special hyperbolic-secant external field

• Hong Cao
• Xi-Jing Liu
• Miao Liu

Nonlinear Dynamics (2022)

• ### Synthesis, Characterization, Properties, and Novel Applications of Fluorescent Nanodiamonds

• Anusuya Boruah
• Binoy K. Saikia

Journal of Fluorescence (2022)

• ### Relaxation of a dense ensemble of spins in diamond under a continuous microwave driving field

• Jeson Chen
• Oliver Y. Chen
• Huan-Cheng Chang

Scientific Reports (2021)

• ### Room Temperature Electrically Detected Nuclear Spin Coherence of NV Centres in Diamond

• H. Morishita
• S. Kobayashi
• N. Mizuochi

Scientific Reports (2020)