Abstract
Quantum memory networks as an intermediate stage in the development of a quantum internet1 will enable a number of significant applications2,3,4,5. To connect and entangle remote quantum memories, it is best to use photons. In previous experiments6,7,8,9,10,11,12,13, entanglement of two memory nodes has been achieved via photon interference. Going beyond the state of the art by entangling many quantum nodes at a distance is highly sought after. Here, we report the entanglement of three remote quantum memories via three-photon interference. We employ laser-cooled atomic ensembles and make use of a ring cavity to enhance the overall efficiency of our memory–photon entanglement. By interfering three single photons from three separate set-ups, we create entanglement of three memories and three photons. Then, by measuring the photons and applying feed-forward, we achieve heralded entanglement between the three memories. Our experiment may be employed as a building block to construct larger and complex quantum networks14,15.
This is a preview of subscription content, access via your institution
Access options
Access Nature and 54 other Nature Portfolio journals
Get Nature+, our best-value online-access subscription
$29.99 / 30 days
cancel any time
Subscribe to this journal
Receive 12 print issues and online access
$209.00 per year
only $17.42 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
Data availability
The data that support the plots within this paper and other findings of this study are available from the corresponding
References
Wehner, S., Elkouss, D. & Hanson, R. Quantum internet: a vision for the road ahead. Science 362, eaam9288 (2018).
Simon, C. Towards a global quantum network. Nat. Photon. 11, 678–680 (2017).
Gottesman, D., Jennewein, T. & Croke, S. Longer-baseline telescopes using quantum repeaters. Phys. Rev. Lett. 109, 070503 (2012).
Kómár, P. et al. A quantum network of clocks. Nat. Phys. 10, 582–587 (2014).
Pikovski, I., Zych, M., Costa, F. & Brukner, Č. Universal decoherence due to gravitational time dilation. Nat. Phys. 11, 668–672 (2015).
Chou, C.-W. et al. Functional quantum nodes for entanglement distribution over scalable quantum networks. Science 316, 1316–1320 (2007).
Moehring, D. L. et al. Entanglement of single-atom quantum bits at a distance. Nature 449, 68–71 (2007).
Yuan, Z.-S. et al. Experimental demonstration of a BDCZ quantum repeater node. Nature 454, 1098–1101 (2008).
Ritter, S. et al. An elementary quantum network of single atoms in optical cavities. Nature 484, 195–200 (2012).
Hofmann, J. et al. Heralded entanglement between widely separated atoms. Science 337, 72–75 (2012).
Usmani, I. et al. Heralded quantum entanglement between two crystals. Nat. Photon. 6, 234–237 (2012).
Bernien, H. et al. Heralded entanglement between solid-state qubits separated by three metres. Nature 497, 86–90 (2013).
Delteil, A. et al. Generation of heralded entanglement between distant hole spins. Nat. Phys. 12, 218–223 (2015).
Wallnöfer, J., Zwerger, M., Muschik, C., Sangouard, N. & Dür, W. Two-dimensional quantum repeaters. Phys. Rev. A 94, 052307 (2016).
Barrett, S. D., Rohde, P. P. & Stace, T. M. Scalable quantum computing with atomic ensembles. New J. Phys. 12, 093032 (2010).
Sangouard, N., Simon, C., de Riedmatten, H. & Gisin, N. Quantum repeaters based on atomic ensembles and linear optics. Rev. Mod. Phys. 83, 33–80 (2011).
Yang, S.-J., Wang, X.-J., Bao, X.-H. & Pan, J.-W. An efficient quantum light–matter interface with sub-second lifetime. Nat. Photon. 10, 381–384 (2016).
Bao, X.-H. et al. Efficient and long-lived quantum memory with cold atoms inside a ring cavity. Nat. Phys. 8, 517–521 (2012).
Yang, S.-J. et al. Highly retrievable spin-wave-photon entanglement source. Phys. Rev. Lett. 114, 210501 (2015).
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).
Jiang, Y., Rui, J., Bao, X.-H. & Pan, J.-W. Dynamical zeroing of spin-wave momentum to suppress motional dephasing in an atomic-ensemble quantum memory. Phys. Rev. A 93, 063819 (2016).
Saffman, M., Walker, T. G. & Molmer, K. Quantum information with Rydberg atoms. Rev. Mod. Phys. 82, 2313–2363 (2010).
Li, L., Dudin, Y. O. & Kuzmich, A. Entanglement between light and an optical atomic excitation. Nature 498, 466–469 (2013).
Li, J. et al. Hong-Ou-Mandel interference between two deterministic collective excitations in an atomic ensemble. Phys. Rev. Lett. 117, 180501 (2016).
Gühne, O. & Tóth, G. Entanglement detection. Phys. Rep. 474, 1–75 (2009).
Choi, K. S., Goban, A., Papp, S. B., van Enk, S. J. & Kimble, H. J. Entanglement of spin waves among four quantum memories. Nature 468, 412–416 (2010).
Pu, Y. F. et al. Experimental entanglement of 25 individually accessible atomic quantum interfaces. Sci. Adv. 4, eaar3931 (2018).
Yan, Z. et al. Establishing and storing of deterministic quantum entanglement among three distant atomic ensembles. Nat. Commun. 8, 718 (2017).
Maring, N. et al. Photonic quantum state transfer between a cold atomic gas and a crystal. Nature 551, 485–488 (2017).
Zhao, T.-M. et al. Entangling different-color photons via time-resolved measurement and active feed forward. Phys. Rev. Lett. 112, 103602 (2014).
Acknowledgements
This work was supported by National Key R&D Program of China (no. 2017YFA0303902), Anhui Initiative in Quantum Information Technologies, National Natural Science Foundation of China, and the Chinese Academy of Sciences.
Author information
Authors and Affiliations
Contributions
X.-H.B. and J.-W.P. conceived and designed the experiment. B.J. and X.-J.W. mainly carried out the experiment and collected the data with assistance from all other authors. B.J., X.-J.W. and X.-H.B. analysed the data. B.J., X.-J.W., X.-H.B. and J.-W.P. wrote the paper with input from all other authors. X.-H.B. and J.-W.P. supervised the whole project.
Corresponding authors
Ethics declarations
Competing interests
The authors declare no competing interests.
Additional information
Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary information
Supplementary Information
Supplementary notes and figures.
Rights and permissions
About this article
Cite this article
Jing, B., Wang, XJ., Yu, Y. et al. Entanglement of three quantum memories via interference of three single photons. Nature Photon 13, 210–213 (2019). https://doi.org/10.1038/s41566-018-0342-x
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/s41566-018-0342-x
This article is cited by
-
Progress in quantum teleportation
Nature Reviews Physics (2023)
-
Rare-earth quantum memories: The experimental status quo
Frontiers of Physics (2023)
-
Towards entanglement distillation between atomic ensembles using high-fidelity spin operations
Communications Physics (2022)
-
Purification for hybrid logical qubit entanglement
Quantum Information Processing (2022)
-
Quantum network is step towards ultrasecure internet
Nature (2021)