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Attractive photons in a quantum nonlinear medium

Firstenberg, Ofer and Peyronel, Thibault and Liang, Qi-Yu and Gorshkov, Alexey V. and Lukin, Mikhail D. and Vuletíc, Vladan (2013) Attractive photons in a quantum nonlinear medium. Nature, 502 (7469). pp. 71-75. ISSN 0028-0836. doi:10.1038/nature12512.

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The fundamental properties of light derive from its constituent particles—massless quanta (photons) that do not interact with one another. However, it has long been known that the realization of coherent interactions between individual photons, akin to those associated with conventional massive particles, could enable a wide variety of novel scientific and engineering applications. Here we demonstrate a quantum nonlinear medium inside which individual photons travel as massive particles with strong mutual attraction, such that the propagation of photon pairs is dominated by a two-photon bound state. We achieve this through dispersive coupling of light to strongly interacting atoms in highly excited Rydberg states. We measure the dynamical evolution of the two-photon wavefunction using time-resolved quantum state tomography, and demonstrate a conditional phase shift exceeding one radian, resulting in polarization-entangled photon pairs. Particular applications of this technique include all-optical switching, deterministic photonic quantum logic and the generation of strongly correlated states of light.

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Lukin, Mikhail D.0000-0002-8658-1007
Additional Information:© 2013 Macmillan Publishers Limited. Received 28 May; accepted 29 July 2013. Published online 25 September 2013. We thank H. P. Büchler, T. Pohl, J. Otterbach, P. Strack, M. Gullans and S. Choi for discussions. This work was supported by the NSF, the CUA, DARPA and the AFOSR Quantum Memories MURI and the Packard Foundations. O.F. acknowledges support from the HQOC. A.V.G. and M.D.L. thank KITP for hospitality. A.V.G. acknowledges funding from the Lee A. DuBridge Foundation and the IQIM, an NSF Physics Frontiers Center with support of the Gordon and Betty Moore Foundation. Author Contributions: The experiment and analysis were carried out by O.F., T.P. and Q.-Y.L. The theoretical modelling was done by A.V.G. All experimental and theoretical work was supervised by M.D.L. and V.V. All authors discussed the results and contributed to the manuscript.
Group:Institute for Quantum Information and Matter
Funding AgencyGrant Number
Defense Advanced Research Projects Agency (DARPA)UNSPECIFIED
Air Force Office of Scientific Research (AFOSR)UNSPECIFIED
David and Lucile Packard FoundationUNSPECIFIED
Lee A. DuBridge FoundationUNSPECIFIED
Institute for Quantum Information and Matter (IQIM)UNSPECIFIED
NSF Physics Frontiers CenterUNSPECIFIED
Gordon and Betty Moore FoundationUNSPECIFIED
Subject Keywords:Atomic and molecular interactions with photons; Nonlinear optics; Quantum optics; Quantum mechanics
Issue or Number:7469
Record Number:CaltechAUTHORS:20131024-083321966
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:42032
Deposited By: Tony Diaz
Deposited On:24 Oct 2013 22:12
Last Modified:10 Nov 2021 04:37

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