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Remote quantum entanglement between two micromechanical oscillators


Entanglement, an essential feature of quantum theory that allows for inseparable quantum correlations to be shared between distant parties, is a crucial resource for quantum networks1. Of particular importance is the ability to distribute entanglement between remote objects that can also serve as quantum memories. This has been previously realized using systems such as warm2,3 and cold atomic vapours4,5, individual atoms6 and ions7,8, and defects in solid-state systems9,10,11. Practical communication applications require a combination of several advantageous features, such as a particular operating wavelength, high bandwidth and long memory lifetimes. Here we introduce a purely micromachined solid-state platform in the form of chip-based optomechanical resonators made of nanostructured silicon beams. We create and demonstrate entanglement between two micromechanical oscillators across two chips that are separated by 20 centimetres . The entangled quantum state is distributed by an optical field at a designed wavelength near 1,550 nanometres. Therefore, our system can be directly incorporated in a realistic fibre-optic quantum network operating in the conventional optical telecommunication band. Our results are an important step towards the development of large-area quantum networks based on silicon photonics.

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Fig. 1: Devices and experimental setup.
Fig. 2: Creation and detection of entanglement between two remote mechanical oscillators.
Fig. 3: Phase sweep of the entangled state.
Fig. 4: Time sweep of the entangled state.


  1. Kimble, H. J. The quantum internet. Nature 453, 1023–1030 (2008).

    ADS  CAS  Article  Google Scholar 

  2. Jensen, K. et al. Quantum memory for entangled continuous-variable states. Nat. Phys. 7, 13–16 (2011).

    CAS  Article  Google Scholar 

  3. Reim, K. F. et al. Single-photon-level quantum memory at room temperature. Phys. Rev. Lett. 107, 053603 (2011).

    ADS  CAS  Article  Google Scholar 

  4. Chou, C. W. et al. Measurement-induced entanglement for excitation stored in remote atomic ensembles. Nature 438, 828–832 (2005).

    ADS  CAS  Article  Google Scholar 

  5. Matsukevich, D. N. et al. Entanglement of remote atomic qubits. Phys. Rev. Lett. 96, 030405 (2006).

    ADS  CAS  Article  Google Scholar 

  6. Ritter, S. et al. An elementary quantum network of single atoms in optical cavities. Nature 484, 195–200 (2012).

    ADS  CAS  Article  Google Scholar 

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

    ADS  CAS  Article  Google Scholar 

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

    ADS  CAS  Article  Google Scholar 

  9. Usmani, I. et al. Heralded quantum entanglement between two crystals. Nat. Photon. 6, 234–237 (2012).

    ADS  CAS  Article  Google Scholar 

  10. Saglamyurek, E. et al. Quantum storage of entangled telecom-wavelength photons in an erbium-doped optical fibre. Nat. Photon. 9, 83–87 (2015).

    ADS  CAS  Article  Google Scholar 

  11. Hensen, B. et al. Loophole-free Bell inequality violation using electron spins separated by 1.3 kilometres. Nature 526, 682–686 (2015).

    ADS  CAS  Article  Google Scholar 

  12. Teufel, J. D. et al. Sideband cooling of micromechanical motion to the quantum ground state. Nature 475, 359–363 (2011).

    ADS  CAS  Article  Google Scholar 

  13. Chan, J. et al. Laser cooling of a nanomechanical oscillator into its quantum ground state. Nature 478, 89–92 (2011).

    ADS  CAS  Article  Google Scholar 

  14. Palomaki, T. A., Teufel, J. D., Simmonds, R. W. & Lehn-ert, K. W. Entangling mechanical motion with microwave fields. Science 342, 710–713 (2013).

    ADS  CAS  Article  Google Scholar 

  15. Riedinger, R. et al. Non-classical correlations between single photons and phonons from a mechanical oscillator. Nature 530, 313–316 (2016).

    ADS  CAS  Article  Google Scholar 

  16. Wollman, E. E. et al. Quantum squeezing of motion in a mechanical resonator. Science 349, 952–955 (2015).

    ADS  MathSciNet  CAS  Article  Google Scholar 

  17. O’Connell, A. D. et al. Quantum ground state and single-phonon control of a mechanical resonator. Nature 464, 697–703 (2010).

    ADS  Article  Google Scholar 

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

    ADS  MathSciNet  CAS  Article  Google Scholar 

  19. Hong, S. et al. Hanbury Brown and Twiss interferometry of single phonons from an optomechanical resonator. Science 358, 203–206 (2017).

    ADS  MathSciNet  CAS  Article  Google Scholar 

  20. Reed, A. P. et al. Faithful conversion of propagating quantum information to mechanical motion. Nat. Phys. 13, 1163–1167 (2017).

    CAS  Article  Google Scholar 

  21. Lee, K. C. et al. Entangling macroscopic diamonds at room temperature. Science 334, 1253–1256 (2011).

    ADS  CAS  Article  Google Scholar 

  22. Meenehan, S. M. et al. Pulsed excitation dynamics of an optomechanical crystal resonator near its quantum ground state of motion. Phys. Rev. X 5, 041002 (2015).

    Google Scholar 

  23. Razavi, M., Piani, M. & Luotkenhaus, N. Quantum repeaters with imperfect memories: cost and scalability. Phys. Rev. A 80, 032301 (2009).

    ADS  Article  Google Scholar 

  24. Bochmann, J., Vainsencher, A., Awschalom, D. D. & Cleland, A. N. Nanomechanical coupling between microwave and optical photons. Nat. Phys. 9, 712–716 (2013).

    CAS  Article  Google Scholar 

  25. Duan, L. M., Lukin, M. D., Cirac, J. I. & Zoller, P. Long-distance quantum communication with atomic ensembles and linear optics. Nature 414, 413–418 (2001).

    ADS  CAS  Article  Google Scholar 

  26. Chan, J. Laser Cooling of an Optomechanical Crystal Resonator to its Quantum Ground State of Motion. Ph.D. thesis, California Institute of Technology (2012).

  27. Børkje, K., Nunnenkamp, A. & Girvin, S. M. Proposal for entangling remote micromechanical oscillators via optical measurements. Phys. Rev. Lett. 107, 123601 (2011).

    ADS  Article  Google Scholar 

  28. Wieczorek, W. et al. Optimal state estimation for cavity optomechanical systems. Phys. Rev. Lett. 114, 223601 (2015).

    ADS  Article  Google Scholar 

  29. Asano, T., Ochi, Y., Takahashi, Y., Kat-suhiro, K. & Noda, S. Photonic crystal nanocavity with a Q factor exceeding eleven million. Opt. Express 25, 1769–1777 (2017).

    ADS  CAS  Article  Google Scholar 

  30. Patel, R. N., Sarabalis, C. J., Jiang, W., Hill, J. T. & Safavi-Naeini, A. H. Engineering phonon leakage in nanomechanical resonators. Phys. Rev. Appl. 8, 041001 (2017).

    Article  Google Scholar 

  31. Maring, N. et al. Photonic quantum state transfer between a cold atomic gas and a crystal. Nature 551, 485–488 (2017).

    ADS  CAS  Article  Google Scholar 

  32. Rueda, A. et al. Efficient microwave to optical photon conversion: an electro-optical realization. Optica 3, 597–604 (2016).

    CAS  Article  Google Scholar 

  33. Higginbotham, A. P. et al. Electro-optic correlations improve an efficient mechanical converter. Preprint at (2017).

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We thank V. Anant, K. Hammerer, J. Hofer, S. Hofer, R. Norte, K. Phelan and J. Slater for discussions and help. We also acknowledge assistance from the Kavli Nanolab Delft, in particular from M. Zuiddam and C. de Boer. This project was supported by the European Commission under the Marie Curie Horizon 2020 initial training programme OMT (grant 722923), Foundation for Fundamental Research on Matter (FOM) Projectruimte grants (15PR3210, 16PR1054), the Vienna Science and Technology Fund WWTF (ICT12-049), the European Research Council (ERC CoG QLev4G, ERC StG Strong-Q), the Austrian Science Fund (FWF) under projects F40 (SFB FOQUS) and P28172, and by the Netherlands Organisation for Scientific Research (NWO/OCW), as part of the Frontiers of Nanoscience programme, as well as through a Vidi grant (680-47-541/994). R.R. is supported by the FWF under project W1210 (CoQuS) and is a recipient of a DOC fellowship of the Austrian Academy of Sciences at the University of Vienna.

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R.R., A.W., I.M., M.A., S.H. and S.G. planned the experiment. A.W., I.M. and S.G. performed the device design and fabrication. R.R., A.W., I.M., C.L., M.A., S.H. and S.G. performed the measurements, analysed the data and wrote the manuscript.

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Correspondence to Sungkun Hong or Simon Gröblacher.

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Riedinger, R., Wallucks, A., Marinković, I. et al. Remote quantum entanglement between two micromechanical oscillators. Nature 556, 473–477 (2018).

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