Attractive photons in a quantum nonlinear medium
Abstract
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.
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.Attached Files
Supplemental Material - nature12512-s1.pdf
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Additional details
- Eprint ID
- 42032
- DOI
- 10.1038/nature12512
- Resolver ID
- CaltechAUTHORS:20131024-083321966
- NSF
- CUA
- Defense Advanced Research Projects Agency (DARPA)
- Air Force Office of Scientific Research (AFOSR)
- David and Lucile Packard Foundation
- HQOC
- Lee A. DuBridge Foundation
- Institute for Quantum Information and Matter (IQIM)
- NSF Physics Frontiers Center
- Gordon and Betty Moore Foundation
- Created
-
2013-10-24Created from EPrint's datestamp field
- Updated
-
2021-11-10Created from EPrint's last_modified field
- Caltech groups
- Institute for Quantum Information and Matter