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:

Integrated optical addressing of an ion qubit

Nature Nanotechnology volume 11, pages 1066–1070 (2016)Cite this article

Subjects

Abstract

The long coherence times and strong Coulomb interactions afforded by trapped ion qubits have enabled realizations of the necessary primitives for quantum information processing1 and the highest-fidelity quantum operations in any qubit to date2,3,4. Although light delivery to each individual ion in a system is essential for general quantum manipulations and readout, experiments so far have employed optical systems that are cumbersome to scale to even a few tens of qubits5. Here we demonstrate lithographically defined nanophotonic waveguide devices for light routing and ion addressing that are fully integrated within a surface-electrode ion trap chip6. Ion qubits are addressed at multiple locations via focusing grating couplers emitting through openings in the trap electrodes to ions trapped 50 μm above the chip; using this light, we perform quantum coherent operations on the optical qubit transition in individual 88Sr+ ions. The grating focuses the beam to a diffraction-limited spot near the ion position with 2 μm 1/e2 radius along the trap axis, and we measure crosstalk errors between 10–2 and 4 × 10–4 at distances 7.5–15 μm from the beam centre. Owing to the scalability of the planar fabrication technique employed, together with the tight focusing and stable alignment afforded by the integration of the optics within the trap chip, this approach presents a path to creating the optical systems required for large-scale trapped-ion quantum information processing.

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

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

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

Figure 1: Device layout.
Figure 2: Focusing grating schematic and characterization.
Figure 3: Addressing and coherent manipulation of individual ions.
Figure 4: Crosstalk error characterization.

Similar content being viewed by others

References

  1. Häffner, H., Roos, C. F. & Blatt, R. Quantum computing with trapped ions. Phys. Rep. 469, 155–203 (2008).

    Article  Google Scholar 

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

    Article  CAS  Google Scholar 

  3. Ballance, C., Harty, T., Linke, N., Sepiol, M. & Lucas, D. Laser-driven quantum logic gates with precision beyond the fault-tolerant threshold. Preprint at http://arxiv.org/abs/1512.04600 (2015).

  4. Gaebler, J. et al. High-fidelity universal gate set for 9Be+ ion qubits. Preprint at http://arxiv.org/abs/1604.00032 (2016).

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

    Article  CAS  Google Scholar 

  6. Chiaverini, J. et al. Surface-electrode architecture for ion-trap quantum information processing. Quantum Inf. Comput. 5, 419–439 (2005).

    CAS  Google Scholar 

  7. Kim, T. H., Herskind, P. F. & Chuang, I. L. Surface-electrode ion trap with integrated light source. Appl. Phys. Lett. 98, 214103 (2011).

    Article  Google Scholar 

  8. VanDevender, A., Colombe, Y., Amini, J., Leibfried, D. & Wineland, D. Efficient fiber optic detection of trapped ion fluorescence. Phys. Rev. Lett. 105, 023001 (2010).

    Article  CAS  Google Scholar 

  9. Streed, E. W., Norton, B. G., Jechow, A., Weinhold, T. J. & Kielpinski, D. Imaging of trapped ions with a microfabricated optic for quantum information processing. Phys. Rev. Lett. 106, 010502 (2011).

    Article  Google Scholar 

  10. Sun, J., Timurdogan, E., Yaacobi, A., Hosseini, E. S. & Watts, M. R. Large-scale nanophotonic phased array. Nature 493, 195–199 (2013).

    Article  CAS  Google Scholar 

  11. Kim, J. & Kim, C. Integrated optical approach to trapped ion quantum computation. Quantum Inf. Comput. 9, 181–202 (2009).

    CAS  Google Scholar 

  12. Crain, S., Mount, E., Baek, S. & Kim, J. Individual addressing of trapped 171Yb+ ion qubits using a microelectromechanical systems-based beam steering system. Appl. Phys. Lett. 105, 181115 (2014).

    Article  Google Scholar 

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

    Article  CAS  Google Scholar 

  14. Chiaverini, J. & Lybarger Jr, W. Laserless trapped-ion quantum simulations without spontaneous scattering using microtrap arrays. Phys. Rev. A 77, 022324 (2008).

    Article  Google Scholar 

  15. Schindler, P. et al. A quantum information processor with trapped ions. New J. Phys. 15, 123012 (2013).

    Article  Google Scholar 

  16. Politi, A., Cryan, M. J., Rarity, J. G., Yu, S. & O'Brien, J. L. Silica-on-silicon waveguide quantum circuits. Science 320, 646–649 (2008).

    Article  CAS  Google Scholar 

  17. Brown, K. et al. Single-qubit-gate error below 10–4 in a trapped ion. Phys. Rev. A 84, 030303 (2011).

    Article  Google Scholar 

  18. Sage, J. M., Kerman, A. J. & Chiaverini, J. Loading of a surface-electrode ion trap from a remote, precooled source. Phys. Rev. A 86, 013417 (2012).

    Article  Google Scholar 

  19. Knoernschild, C. et al. Independent individual addressing of multiple neutral atom qubits with a micromirror-based beam steering system. Appl. Phys. Lett. 97, 134101 (2010).

    Article  Google Scholar 

  20. Nägerl, H. C. et al. Laser addressing of individual ions in a linear ion trap. Phys. Rev. A 60, 145–148 (1999).

    Article  Google Scholar 

  21. Warring, U. et al. Individual-ion addressing with microwave field gradients. Phys. Rev. Lett. 110, 173002 (2013).

    Article  CAS  Google Scholar 

  22. Mehta, K. K. & Ram, R. J . Precise and diffraction-limited waveguide-to-free-space focusing gratings. Preprint at http://arxiv.org/abs/1607.00107 (2016).

  23. Mehta, K. et al. Ion traps fabricated in a CMOS foundry. Appl. Phys. Lett. 105, 044103 (2014).

    Article  Google Scholar 

  24. Orcutt, J. S. et al. Open foundry platform for high-performance electronic-photonic integration. Opt. Express 20, 12222–12232 (2012).

    Article  Google Scholar 

  25. Taillaert, D. et al. An out-of-plane grating coupler for efficient butt-coupling between compact planar waveguides and single-mode fibers. IEEE J. Quantum Electr. 38, 949–955 (2002).

    Article  CAS  Google Scholar 

  26. Gröblacher, S., Hill, J. T., Safavi-Naeini, A. H., Chan, J. & Painter, O. Highly efficient coupling from an optical fiber to a nanoscale silicon optomechanical cavity. Appl. Phys. Lett. 103, 181104 (2013).

    Article  Google Scholar 

  27. Xiong, C., Pernice, W. H. & Tang, H. X. Low-loss, silicon integrated, aluminum nitride photonic circuits and their use for electro-optic signal processing. Nano Lett. 12, 3562–3568 (2012).

    Article  CAS  Google Scholar 

  28. Leibfried, D., Knill, E., Ospelkaus, C. & Wineland, D. Transport quantum logic gates for trapped ions. Phys. Rev. A 76, 032324 (2007).

    Article  Google Scholar 

  29. de Clercq, L. E. et al. Parallel transport quantum logic gates with trapped ions. Phys. Rev. Lett. 116, 080502 (2016).

    Article  Google Scholar 

  30. Harlander, M., Brownnutt, M., Hänsel, W. & Blatt, R. Trapped-ion probing of light-induced charging effects on dielectrics. N. J. Phys. 12, 093035 (2010).

    Article  Google Scholar 

  31. Eltony, A. M., Wang, S. X., Akselrod, G. M., Herskind, P. F. & Chuang, I. L. Transparent ion trap with integrated photodetector. Appl. Phys. Lett. 102, 054106 (2013).

    Article  Google Scholar 

  32. Daldosso, N. et al. Comparison among various Si3N4 waveguide geometries grown within a CMOS fabrication pilot line. J. Lightwave Technol. 22, 1734–1740 (2004).

    Article  CAS  Google Scholar 

  33. James, D. F. Quantum dynamics of cold trapped ions with application to quantum computation. Appl. Phys. B 66, 181–190 (1998).

    Article  CAS  Google Scholar 

  34. Gorin, A., Jaouad, A., Grondin, E., Aimez, V. & Charette, P. Fabrication of silicon nitride waveguides for visible-light using PECVD: a study of the effect of plasma frequency on optical properties. Opt. Express 16, 13509–13516 (2008).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

We thank I. Chuang for initial discussions of the approach; J. Sun, A. Atabaki, A. Eltony and M. Gutierrez for helpful discussions; the MIT Microsystems Technology Laboratory Staff, the Nanostructures Lab and M. Mondol in particular for help with electron beam lithography; and P. Murphy, J. Porter and C. Thoummaraj for assistance with ion-trap fabrication and packaging. This work was partially funded by NSF program ECCS-1408495. K.K.M. acknowledges support from a DOE Science Graduate Fellowship and the NSF iQuISE IGERT programme.

This work was sponsored by the Assistant Secretary of Defense for Research and Engineering under Air Force Contract No. FA8721-05-C-0002. Opinions, interpretations, conclusions and recommendations are those of the authors and are not necessarily endorsed by the US government.

Author information

Authors and Affiliations

  1. Department of Electrical Engineering & Computer Science and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, 02139, Massachusetts, USA

    Karan K. Mehta & Rajeev J. Ram

  2. Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, 02420, Massachusetts, USA

    Colin D. Bruzewicz, Robert McConnell, Jeremy M. Sage & John Chiaverini

Authors
  1. Karan K. Mehta
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Colin D. Bruzewicz
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Robert McConnell
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Rajeev J. Ram
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Jeremy M. Sage
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. John Chiaverini
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

K.K.M., R.J.R., J.M.S. and J.C. designed the experiments. K.K.M. designed, fabricated and tested the waveguide devices with supervision from R.J.R. C.D.B., R.M., J.M.S. and J.C. designed and constructed the vacuum apparatus and laser system used for the ion trap device characterization, and K.K.M., J.M.S., and J.C. performed the single ion experiments with the device. K.K.M. prepared the manuscript and all authors reviewed it and discussed the results.

Corresponding author

Correspondence to Karan K. Mehta.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary information (PDF 199 kb)

Supplementary Movie 1

Supplementary Movie 1 (MP4 9371 kb)

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Mehta, K., Bruzewicz, C., McConnell, R. et al. Integrated optical addressing of an ion qubit. Nature Nanotech 11, 1066–1070 (2016). https://doi.org/10.1038/nnano.2016.139

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/nnano.2016.139

This article is cited by

Search

Advanced 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