Skip to main content

Thank you for visiting 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.

Trapped-ion antennae for the transmission of quantum information


More than 100 years ago, Hertz succeeded in transmitting signals over a few metres to a receiving antenna using an electromagnetic oscillator, thus proving the electromagnetic theory1 developed by Maxwell. Since this seminal work, technology has developed, and various oscillators are now available at the quantum mechanical level. For quantized electromagnetic oscillations, atoms in cavities can be used to couple electric fields2,3. However, a quantum mechanical link between two mechanical oscillators (such as cantilevers4,5 or the vibrational modes of trapped atoms6 or ions7,8) has been rarely demonstrated and has been achieved only indirectly. Examples include the mechanical transport of atoms carrying quantum information9 or the use of spontaneously emitted photons10. Here we achieve direct coupling between the motional dipoles of separately trapped ions over a distance of 54 micrometres, using the dipole–dipole interaction as a quantum mechanical transmission line11. This interaction is small between single trapped ions, but the coupling is amplified by using additional trapped ions as antennae. With three ions in each well, the interaction is increased by a factor of seven compared to the single-ion case. This enhancement facilitates bridging of larger distances and relaxes the constraints on the miniaturization of trap electrodes. The system provides a building block for quantum computers and opportunities for coupling different types of quantum systems.

This is a preview of subscription content

Access options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Figure 1: Creation of trap potential.
Figure 2: Energy exchange between two trapped ions over a distance of 54 µm.
Figure 3: Demonstration of avoided crossing derived from sideband spectra.
Figure 4: Experimentally observed dipole–dipole coupling for various ion configurations in a double-well potential.


  1. 1

    Hertz, H. Über die Grundgleichungen der Electrodynamik für bewegte Körper. Ann. Phys. Chem. 277, 369–399 (1890)

    ADS  Article  Google Scholar 

  2. 2

    Kuhr, S. et al. Ultrahigh finesse Fabry-Perot superconducting resonator. Appl. Phys. Lett. 90, 164101 (2007)

    ADS  Article  Google Scholar 

  3. 3

    Gleyzes, S. et al. Quantum jumps of light recording the birth and death of a photon in a cavity. Nature 446, 297–300 (2007)

    ADS  CAS  Article  Google Scholar 

  4. 4

    Anetsberger, G. et al. Near-field cavity optomechanics with nanomechanical oscillators. Nature Phys. 5, 909–914 (2009)

    ADS  CAS  Article  Google Scholar 

  5. 5

    Schliesser, A., Del'Haye, P., Nooshi, N., Vahala, K. J. & Kippenberg, T. J. Radiation pressure cooling of a micromechanical oscillator using dynamical backaction. Phys. Rev. Lett. 97, 243905 (2006)

    ADS  CAS  Article  Google Scholar 

  6. 6

    Kinoshita, T., Wenger, T. & Weiss, D. S. A quantum Newton's cradle. Nature 440, 900–903 (2006)

    ADS  CAS  Article  Google Scholar 

  7. 7

    Leibfried, D., Blatt, R., Monroe, C. & Wineland, D. Quantum dynamics of single trapped ions. Rev. Mod. Phys. 75, 281–324 (2003)

    ADS  CAS  Article  Google Scholar 

  8. 8

    Monroe, C., Meekhof, D. M., King, B. E. & Wineland, D. J. A “Schrödinger Cat” superposition state of an atom. Science 272, 1131–1136 (1996)

    ADS  MathSciNet  CAS  Article  Google Scholar 

  9. 9

    Jost, J. D. et al. Entangled mechanical oscillators. Nature 459, 683–685 (2009)

    ADS  CAS  Article  Google Scholar 

  10. 10

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

    ADS  CAS  Article  Google Scholar 

  11. 11

    Cirac, J. I. & Zoller, P. A scalable quantum computer with ions in an array of microtraps. Nature 404, 579–581 (2000)

    ADS  CAS  Article  Google Scholar 

  12. 12

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

    Article  Google Scholar 

  13. 13

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

    ADS  CAS  Article  Google Scholar 

  14. 14

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

    ADS  CAS  Article  Google Scholar 

  15. 15

    Seidelin, S. et al. Microfabricated surface-electrode ion trap for scalable quantum information processing. Phys. Rev. Lett. 96, 253003 (2006)

    ADS  CAS  Article  Google Scholar 

  16. 16

    Leibrandt, D. R. et al. Modeling ion trap thermal noise coherence. Quant. Inform. Comput. 7, 052–072 (2007)

    MathSciNet  CAS  Google Scholar 

  17. 17

    Labaziewicz, J. et al. Suppression of heating rates in cyrogenic surface-electrode ion traps. Phys. Rev. Lett. 100, 013001 (2008)

    ADS  Article  Google Scholar 

  18. 18

    Cirac, J. I. & Zoller, P. Quantum computations with cold trapped ions. Phys. Rev. Lett. 74, 4091–4094 (1995)

    ADS  CAS  Article  Google Scholar 

  19. 19

    Schulz, S. A., Poschinger, U., Ziesel, F. & Schmidt-Kaler, F. Sideband cooling and coherent dynamics in a microchip multi-segmented ion trap. N. J. Phys. 10, 045007 (2008)

    Article  Google Scholar 

  20. 20

    Roos, C. F. et al. Quantum state engineering on an optical transition and decoherence in a Paul trap. Phys. Rev. Lett. 83, 4713–4716 (1999)

    ADS  CAS  Article  Google Scholar 

  21. 21

    Meekhof, D. M., Monroe, C., King, B. E., Itano, W. M. & Wineland, D. J. Generation of nonclassical motional states of a trapped atom. Phys. Rev. Lett. 76, 1796–1799 (1996)

    ADS  CAS  Article  Google Scholar 

  22. 22

    Turchette, Q. A. et al. Heating of trapped ions from the quantum ground state. Phys. Rev. A 61, 063418 (2000)

    ADS  Article  Google Scholar 

  23. 23

    Brown, K. R. et al. Coupled quantized mechanical oscillators. Nature doi:10.1038/nature09721 (this issue).

  24. 24

    Benhelm, J. et al. Towards fault-tolerant quantum computing with trapped ions. Nature Phys. 4, 463–466 (2008)

    ADS  CAS  Article  Google Scholar 

  25. 25

    Sørensen, A. & Mølmer, K. Quantum computation with ions in thermal motion. Phys. Rev. Lett. 82, 1971–1974 (1999)

    ADS  Article  Google Scholar 

  26. 26

    Raussendorf, R., Browne, D. E. & Briegel, H. J. Measurement-based quantum computation on cluster states. Phys. Rev. A 68, 022312 (2003)

    ADS  Article  Google Scholar 

  27. 27

    Urban, E. et al. Observation of Rydberg blockade between two atoms. Nature Phys. 5, 110–114 (2009)

    ADS  CAS  Article  Google Scholar 

  28. 28

    Zipkes, C., Palzer, S., Sias, C. & Köhl, M. A trapped single ion inside a Bose-Einstein condensate. Nature 464, 388–391 (2010)

    ADS  CAS  Article  Google Scholar 

  29. 29

    Schmid, S., Härter, A. & Denschlag, J. H. Dynamics of a cold trapped ion in a Bose-Einstein condensate. Phys. Rev. Lett. 105, 133202 (2010)

    ADS  Article  Google Scholar 

  30. 30

    Home, J. P. & Steane, A. M. Electrode configuration for fast separation of trapped ions. Quant. Inform. Comput. 6, 289–325 (2006)

    CAS  MATH  Google Scholar 

Download references


We thank H. Häffner for discussions at an early state of the project. We acknowledge the support of the EU STREP project MICROTRAP, the Austrian Science Fund (FWF), the EU network SCALA, the European Research Council (ERC) and the Institut für Quanteninformation GmbH.

Author information




The experiments were performed by M.H., R.L. and W.H.; M.H., M.B., R.L., W.H. and R.B. contributed to the set-up; the data analysis was performed by M.H. and W.H.; the original idea was devised by W.H. and R.B.; and all authors contributed to the discussion of the results and participated in manuscript preparation.

Corresponding author

Correspondence to R. Blatt.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

PowerPoint slides

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Harlander, M., Lechner, R., Brownnutt, M. et al. Trapped-ion antennae for the transmission of quantum information. Nature 471, 200–203 (2011).

Download citation

Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links