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Raman quantum memory of photonic polarized entanglement


The storage of photonic entanglement is central to the achievement of long-distance quantum communication based on quantum repeaters and scalable linear optical quantum computation. Among the memory protocols reported to date, the Raman scheme has the advantages of being broadband and high-speed, resulting in a huge potential in quantum networks. To date there have been no reports on the storage of photonic polarized entanglement using the Raman protocol. Here, two storage experiments using the Raman scheme are reported: (1) heralded single-photon entanglement of the path and polarization storage in a cold atomic ensemble, and (2) polarization entanglement storage in two cold atomic ensembles. The experimental data clearly show that the quantum entanglement is preserved in this memory platform. Our work shows great promise for the establishment of quantum networks in high-speed communications.

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Figure 1: Energy diagram and experimental set-up.
Figure 2: Interference of single photon for input and output.
Figure 3: Density matrices for input and output.
Figure 4: Reconstructed density matrix before and after storage.
Figure 5: Two-photon interference before and after storage.


  1. 1

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

    ADS  Article  Google Scholar 

  2. 2

    Lvovsky, A. I., Sanders, B. C. & Tittel, W. Optical quantum memory. Nature Photon. 3, 706–714 (2009).

    ADS  Article  Google Scholar 

  3. 3

    Bussières, F. et al. Perspective applications of optical quantum memories. J. Mod. Opt. 60, 1519–1537 (2013).

    ADS  MathSciNet  Article  Google Scholar 

  4. 4

    Briegel, H.-J., Dür, W., Cirac, J. I. & Zoller, P. Quantum repeaters: the role of imperfect local operations in quantum communication. Phys. Rev. Lett. 81, 5932–5935 (1998).

    ADS  Article  Google Scholar 

  5. 5

    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  Article  Google Scholar 

  6. 6

    England, D. G. et al. High-fidelity polarization storage in a gigahertz bandwidth quantum memory. J. Phys. B. 45, 124008 (2012).

    ADS  Article  Google Scholar 

  7. 7

    Zhang, H. J. et al. Preparation and storage of frequency-uncorrelated entangled photons from cavity-enhanced spontaneous parametric downconversion. Nature Photon. 5, 628–632 (2011).

    ADS  Article  Google Scholar 

  8. 8

    Dai, H.-N. et al. Holographic storage of biphoton entanglement. Phys. Rev. Lett. 108, 210501 (2012).

    ADS  Article  Google Scholar 

  9. 9

    Harris, S. E., Field, J. E. & Imamoglu, A. Nonlinear optical processes using electromagnetically induced transparency. Phys. Rev. Lett. 64, 1107–1110 (1990).

    ADS  Article  Google Scholar 

  10. 10

    Chanelière, T. et al. Storage and retrieval of single photons transmitted between remote quantum memories. Nature 438, 833–836 (2005).

    ADS  Article  Google Scholar 

  11. 11

    Xu, Z. et al. Long lifetime and high-fidelity quantum memory of photonic polarization qubit by lifting Zeeman degeneracy. Phys. Rev. Lett. 111, 240503 (2013).

    ADS  Article  Google Scholar 

  12. 12

    Kozhekin, A. E., Mølmer, K. & Polzik, E. Quantum memory for light. Phys. Rev. A 62, 033809 (2000).

    ADS  Article  Google Scholar 

  13. 13

    Nunn, J. et al. Mapping broadband single-photon wave packets into an atomic memory. Phys. Rev. A 75, 011401R (2007).

    ADS  Article  Google Scholar 

  14. 14

    Reim, K. F. et al. Toward high-speed optical quantum memories. Nature Photon. 4, 218–221 (2010).

    ADS  Article  Google Scholar 

  15. 15

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

    ADS  Article  Google Scholar 

  16. 16

    Ding, D.-S. et al. Quantum storage of orbital angular momentum entanglement in an atomic ensemble. Phys. Rev. Lett. 114, 050502 (2015).

    ADS  Article  Google Scholar 

  17. 17

    Michelberger, P. S., Champion, T. F. M., Sprague, M. R. & Kaczmarek, I. A. Interfacing GHz-bandwidth heralded single photons with a room-temperature Raman quantum memory. Preprint at (2014).

  18. 18

    Bustard, P. J., Lausten, R., England, D. G. & Sussman, B. J. Toward quantum processing in molecules: a THz-bandwidth coherent memory for light. Phys. Rev. Lett. 111, 083901 (2013).

    ADS  Article  Google Scholar 

  19. 19

    England, D. G., Bustard, P. J., Nunn, J., Lausten, R. & Sussman, B. J. From photons to phonons and back: a THz optical memory in diamond. Phys. Rev. Lett. 111, 243601 (2013).

    ADS  Article  Google Scholar 

  20. 20

    Moiseev, S. A. & Kröll, S. Complete reconstruction of the quantum state of a single-photon wave packet absorbed by a Doppler-broadened transition. Phys. Rev. Lett. 87, 173601 (2001).

    ADS  Article  Google Scholar 

  21. 21

    Kraus, B. et al. Quantum memory for nonstationary light fields based on controlled reversible inhomogeneous broadening. Phys. Rev. A 73, 020302(R) (2006).

    ADS  Article  Google Scholar 

  22. 22

    Alexander, A. L., Longdell, J. J., Sellars, M. J. & Manson, N. B. Photon echoes produced by switching electric fields. Phys. Rev. Lett. 96, 043602 (2006).

    ADS  Article  Google Scholar 

  23. 23

    Tittel, W. et al. Photon-echo quantum memory in solid state systems. Laser Photon. Rev. 4, 244–267 (2010).

    ADS  Article  Google Scholar 

  24. 24

    Afzelius, M., Simon, C., De Riedmatten, H. & Gisin, N. Multimode quantum memory based on atomic frequency combs. Phys. Rev. A 79, 052329 (2009).

    ADS  Article  Google Scholar 

  25. 25

    Buchler, B. C., Hosseini, M., Hetet, G., Sparkes, B. M. & Lam, P. K. Precision spectral manipulation of optical pulses using a coherent photon echo memory. Opt. Lett. 35, 1091–1093 (2010).

    ADS  Article  Google Scholar 

  26. 26

    Hosseini, M., Sparkes, B. M., Campbell, G., Lam, P. K. & Buchler, B. C. High efficiency coherent optical memory with warm rubidium vapour. Nature Commun. 2, 174 (2011).

    ADS  Article  Google Scholar 

  27. 27

    Fiore, V. et al. Storing optical information as a mechanical excitation in a silica optomechanical resonator. Phys. Rev. Lett. 107, 133601 (2011).

    ADS  Article  Google Scholar 

  28. 28

    Julsgaard, B., Sherson, J., Cirac, J. I., Fiurašek, J. & Polzik, E. S. Experimental demonstration of quantum memory for light. Nature 432, 482–486 (2004).

    ADS  Article  Google Scholar 

  29. 29

    Julsgaard, B., Kozhekin, A. & Polzik, E. S. Experimental long-lived entanglement of two macroscopic objects. Nature 413, 400–403 (2001).

    ADS  Article  Google Scholar 

  30. 30

    Choi, K. S., Deng, H., Laurat, J. & Kimble, H. J. Mapping photonic entanglement into and out of a quantum memory. Nature 452, 67–71 (2008).

    ADS  Article  Google Scholar 

  31. 31

    Saglamyurek, E. et al. Broadband waveguide quantum memory for entangled photons. Nature 469, 512–515 (2011).

    ADS  Article  Google Scholar 

  32. 32

    Clausen, C. et al. Quantum storage of photonic entanglement in a crystal. Nature 469, 508–511 (2011).

    ADS  Article  Google Scholar 

  33. 33

    Liu, Y., Wu, J.-H., Shi, B.-S. & Guo, G.-C. Realization of a two-dimensional magneto-optical trap with a high optical depth. Chinese Phys. Lett. 29, 024205 (2012).

    ADS  Article  Google Scholar 

  34. 34

    Kuzmich, A. et al. Generation of nonclassical photon pairs for scalable quantum communication with atomic ensembles. Nature 423, 731–734 (2003).

    ADS  Article  Google Scholar 

  35. 35

    Ding, D.-S., Zhou, Z.-Y., Shi, B.-S. & Guo, G.-C. Single-photon-level quantum image memory based on cold atomic ensembles. Nature Commun 4, 2527 (2013).

    ADS  Article  Google Scholar 

  36. 36

    Clauser, J. F., Horne, M. A., Shimony, A. & Holt, R. A. Proposed experiment to test local hidden-variable theories. Phys. Rev. Lett. 23, 880–884 (1969).

    ADS  Article  Google Scholar 

  37. 37

    Chen, S. et al. Demonstration of a stable atom–photon entanglement source for quantum repeaters. Phys. Rev. Lett. 99, 180505 (2007).

    ADS  Article  Google Scholar 

  38. 38

    Liao, K. et al. Subnatural-linewidth polarization-entangled photon pairs with controllable temporal length. Phys. Rev. Lett. 112, 243602 (2014).

    ADS  Article  Google Scholar 

  39. 39

    Hamel, D. R. et al. Direct generation of three-photon polarization entanglement. Nature Photon. 8, 801–807 (2014).

    ADS  Article  Google Scholar 

  40. 40

    Barz, S., Cronenberg, G., Zeilinger, A. & Walther, P. Heralded generation of entangled photon pairs. Nature Photon. 4, 553–556 (2010).

    ADS  Article  Google Scholar 

  41. 41

    Wagenknecht, C. et al. Experimental demonstration of a heralded entanglement source. Nature Photon. 4, 549–552 (2010).

    ADS  Article  Google Scholar 

  42. 42

    Surmacz, K. et al. Efficient spatially resolved multimode quantum memory. Phys. Rev. A 78, 033806 (2008).

    ADS  Article  Google Scholar 

  43. 43

    Zhao, B. et al. A millisecond quantum memory for scalable quantum networks. Nature Phys. 5, 95–99 (2008).

    ADS  Article  Google Scholar 

  44. 44

    Bao, X.-H. et al. Efficient and long-lived quantum memory with cold atoms inside a ring cavity. Nature Phys. 8, 517–521 (2012).

    ADS  Article  Google Scholar 

  45. 45

    Radnaev, A. G. et al. A quantum memory with telecom-wavelength conversion. Nature Phys. 6, 894–899 (2010).

    ADS  Article  Google Scholar 

  46. 46

    Heinze, G., Hubrich, C. & Halfmann, T. Stopped light and image storage by electromagnetically induced transparency up to the regime of one minute. Phys. Rev. Lett. 111, 033601 (2013).

    ADS  Article  Google Scholar 

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The authors thank Yuan Sun for reading and commenting on this manuscript. This work was supported by the National Fundamental Research Program of China (grant no. 2 011CBA00200), the National Natural Science Foundation of China (grants nos. 11174271, 61275115 and 61435011), the Youth Innovation Fund from University of Science and Technology of China (grant no. ZC 9850320804) and the Innovation Fund from Chinese Academy of Sciences.

Author information




B.S.S. conceived the idea and experiment. W.Z. and D.S.D. designed and carried out the experiments with assistance from Z.Y.Z. and S.S. D.S.D. and W.Z. carried out data analysis. D.S.D. wrote the manuscript. B.S.S. and G.C.G. supervised the project.

Corresponding author

Correspondence to Bao-Sen Shi.

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The authors declare no competing financial interests.

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Ding, DS., Zhang, W., Zhou, ZY. et al. Raman quantum memory of photonic polarized entanglement. Nature Photon 9, 332–338 (2015).

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