The reversible transfer of quantum states of light into and out of matter constitutes an important building block for future applications of quantum communication: it will allow the synchronization of quantum information1, and the construction of quantum repeaters2 and quantum networks3. Much effort has been devoted to the development of such quantum memories1, the key property of which is the preservation of entanglement during storage. Here we report the reversible transfer of photon–photon entanglement into entanglement between a photon and a collective atomic excitation in a solid-state device. Towards this end, we employ a thulium-doped lithium niobate waveguide in conjunction with a photon-echo quantum memory protocol4, and increase the spectral acceptance from the current maximum5 of 100 megahertz to 5 gigahertz. We assess the entanglement-preserving nature of our storage device through Bell inequality violations6 and by comparing the amount of entanglement contained in the detected photon pairs before and after the reversible transfer. These measurements show, within statistical error, a perfect mapping process. Our broadband quantum memory complements the family of robust, integrated lithium niobate devices7. It simplifies frequency-matching of light with matter interfaces in advanced applications of quantum communication, bringing fully quantum-enabled networks a step closer.
Subscribe to Journal
Get full journal access for 1 year
only $3.90 per issue
All prices are NET prices.
VAT will be added later in the checkout.
Tax calculation will be finalised during checkout.
Rent or Buy article
Get time limited or full article access on ReadCube.
All prices are NET prices.
Lvovsky, A. I. & Sanders, B. C. &. Tittel, W. Optical quantum memory. Nature Photon. 3, 706–714 (2009)
Sangouard, N., Simon, C., de Riedmatten, H. & Gisin, N. Quantum repeaters based on atomic ensembles and linear optics. Preprint at 〈http://arxiv.org/abs/0906.2699〉 (2009)
Kimble, H. J. The quantum Internet. Nature 453, 1023–1030 (2008)
de Riedmatten, H., Afzelius, M., Staudt, M. U., Simon, C. & Gisin, N. A solid-state light–matter interface at the single-photon level. Nature 456, 773–777 (2008)
Usmani, I., Afzelius, M., de Riedmatten, H. & Gisin, N. Mapping multiple photonic qubits into and out of one solid-state atomic ensemble. Nature Commun. 1, 1–7 (2010)
Pan, J.-W., Chen, Z.-B., Żukowski, M., Weinfurter, H. & Zeilinger, A. Multi-photon entanglement and interferometry. Preprint at 〈http://arxiv.org/abs/0805.2853〉 (2008)
Sohler, W. et al. Integrated optical devices in lithium niobate. Opt. Photon. News 24–31. (January 2008)
Gisin, N., Ribordy, G., Tittel, W. & Zbinden, H. Quantum cryptography. Rev. Mod. Phys. 74, 145–195 (2002)
Julsgaard, B., Sherson, J. & Cirac, J. I. J. Fiurášek, J. & Polzik, E. S. Experimental demonstration of quantum memory for light. Nature 432, 482–486 (2004)
Chanelière, T. et al. Storage and retrieval of single photons transmitted between remote quantum memories. Nature 438, 833–836 (2005)
Eisaman, M. D. et al. Electromagnetically induced transparency with tunable single-photon pulses. Nature 438, 837–841 (2005)
Honda, K. et al. Storage and retrieval of a squeezed vacuum. Phys. Rev. Lett. 100, 093601 (2008)
Appel, J., Figueroa, E., Korystov, D., Lobino, M. & Lvovsky, A. Quantum memory for squeezed light. Phys. Rev. Lett. 100, 093602 (2008)
Hedges, M. P., Longdell, J. J., Li, Y. & Sellars, M. J. Efficient quantum memory for light. Nature 465, 1052–1056 (2010)
Boozer, A. D. et al. Reversible state transfer between light and a single trapped atom. Phys. Rev. Lett. 98, 193601 (2007)
Choi, C. S. & Deng, H. Laurat, J. & Kimble, H. J. Mapping photonic entanglement into and out of a quantum memory. Nature 452, 67–71 (2008)
Akiba, K. & Kashiwagi, K. Arikawa, M. & Kozuma, M. Storage and retrieval of non-classical photon pairs and conditional single photons generated by the parametric down-conversion process. N. J. Phys. 11, 013049 (2009)
Jin, X.-M. et al. Quantum interface between frequency-uncorrelated down-converted entanglement and atomic-ensemble quantum memory. Preprint at 〈http://arxiv.org/abs/1004.4691〉 (2010)
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 a photon and a collective atomic excitation. Phys. Rev. Lett. 95, 040405 (2005)
Yuan, Z.-S. et al. Experimental demonstration of a BDCZ quantum repeater node. Nature 454, 1098–1101 (2008)
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)
Togan, E. et al. Quantum entanglement between an optical photon and a solid-state spin qubit. Nature 466, 730–734 (2010)
Longdell, J., Fraval, E., Sellars, M. & Manson, N. Stopped light with storage times greater than one second using electromagnetically induced transparency in a solid. Phys. Rev. Lett. 95, 063601 (2005)
Marcikic, I. et al. Time-bin entangled qubits for quantum communication created by femtosecond pulses. Phys. Rev. A 66, 062308 (2002)
Sinclair, N. et al. Spectroscopic investigations of a Ti:Tm:LiNbO3 waveguide for photon-echo quantum memory. J. Lumin. 130, 1586–1593 (2010)
Altepeter, J. B. & Jeffrey, E. R. &. Kwiat, P. G. Photonic state tomography. Adv. At. Mol. Opt. Phys. 52, 105–159 (2005)
Plenio, M. B. & Virmani, S. An introduction to entanglement measures. Quant. Inf. Comput. 7, 1–51 (2007)
Clausen, C. et al. Quantum storage of photonic entanglement in a crystal. Nature 10.1038/nature09662 (this issue)
This work is supported by NSERC, QuantumWorks, General Dynamics Canada, iCORE (now part of Alberta Innovates), CFI, AAET and FQRNT. We thank C. La Mela, T. Chanelière, T. Stuart, V. Kiselyov and C. Dascollas for help during various stages of the experiment, C. Simon, K. Rupavatharam and N. Gisin for discussions, and A. Lvovsky for lending us a single-photon detector.
The authors declare no competing financial interests.
About this article
Cite this article
Saglamyurek, E., Sinclair, N., Jin, J. et al. Broadband waveguide quantum memory for entangled photons. Nature 469, 512–515 (2011). https://doi.org/10.1038/nature09719
Applied Physics Letters (2021)
Applied Physics Reviews (2021)
Physical Review Letters (2021)
Materials Today Communications (2021)
PRX Quantum (2021)