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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Kimble, H. J. The quantum internet. Nature 453, 1023–1030 (2008).
Jensen, K. et al. Quantum memory for entangled continuous-variable states. Nat. Phys. 7, 13–16 (2011).
Reim, K. F. et al. Single-photon-level quantum memory at room temperature. Phys. Rev. Lett. 107, 053603 (2011).
Chou, C. W. et al. Measurement-induced entanglement for excitation stored in remote atomic ensembles. Nature 438, 828–832 (2005).
Matsukevich, D. N. et al. Entanglement of remote atomic qubits. Phys. Rev. Lett. 96, 030405 (2006).
Ritter, S. et al. An elementary quantum network of single atoms in optical cavities. Nature 484, 195–200 (2012).
Moehring, D. L. et al. Entanglement of single-atom quantum bits at a distance. Nature 449, 68–71 (2007).
Jost, J. D. et al. Entangled mechanical oscillators. Nature 459, 683–685 (2009).
Usmani, I. et al. Heralded quantum entanglement between two crystals. Nat. Photon. 6, 234–237 (2012).
Saglamyurek, E. et al. Quantum storage of entangled telecom-wavelength photons in an erbium-doped optical fibre. Nat. Photon. 9, 83–87 (2015).
Hensen, B. et al. Loophole-free Bell inequality violation using electron spins separated by 1.3 kilometres. Nature 526, 682–686 (2015).
Teufel, J. D. et al. Sideband cooling of micromechanical motion to the quantum ground state. Nature 475, 359–363 (2011).
Chan, J. et al. Laser cooling of a nanomechanical oscillator into its quantum ground state. Nature 478, 89–92 (2011).
Palomaki, T. A., Teufel, J. D., Simmonds, R. W. & Lehn-ert, K. W. Entangling mechanical motion with microwave fields. Science 342, 710–713 (2013).
Riedinger, R. et al. Non-classical correlations between single photons and phonons from a mechanical oscillator. Nature 530, 313–316 (2016).
Wollman, E. E. et al. Quantum squeezing of motion in a mechanical resonator. Science 349, 952–955 (2015).
O’Connell, A. D. et al. Quantum ground state and single-phonon control of a mechanical resonator. Nature 464, 697–703 (2010).
Chu, Y. et al. Quantum acoustics with superconducting qubits. Science 358, 199–202 (2017).
Hong, S. et al. Hanbury Brown and Twiss interferometry of single phonons from an optomechanical resonator. Science 358, 203–206 (2017).
Reed, A. P. et al. Faithful conversion of propagating quantum information to mechanical motion. Nat. Phys. 13, 1163–1167 (2017).
Lee, K. C. et al. Entangling macroscopic diamonds at room temperature. Science 334, 1253–1256 (2011).
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).
Razavi, M., Piani, M. & Luotkenhaus, N. Quantum repeaters with imperfect memories: cost and scalability. Phys. Rev. A 80, 032301 (2009).
Bochmann, J., Vainsencher, A., Awschalom, D. D. & Cleland, A. N. Nanomechanical coupling between microwave and optical photons. Nat. Phys. 9, 712–716 (2013).
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).
Chan, J. Laser Cooling of an Optomechanical Crystal Resonator to its Quantum Ground State of Motion. Ph.D. thesis, California Institute of Technology (2012).
Børkje, K., Nunnenkamp, A. & Girvin, S. M. Proposal for entangling remote micromechanical oscillators via optical measurements. Phys. Rev. Lett. 107, 123601 (2011).
Wieczorek, W. et al. Optimal state estimation for cavity optomechanical systems. Phys. Rev. Lett. 114, 223601 (2015).
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).
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).
Maring, N. et al. Photonic quantum state transfer between a cold atomic gas and a crystal. Nature 551, 485–488 (2017).
Rueda, A. et al. Efficient microwave to optical photon conversion: an electro-optical realization. Optica 3, 597–604 (2016).
Higginbotham, A. P. et al. Electro-optic correlations improve an efficient mechanical converter. Preprint at https://arxiv.org/abs/1712.06535 (2017).
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.
The authors declare no competing interests.
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Riedinger, R., Wallucks, A., Marinković, I. et al. Remote quantum entanglement between two micromechanical oscillators. Nature 556, 473–477 (2018). https://doi.org/10.1038/s41586-018-0036-z
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