Characterizing quantum channels with non-separable states of classical light

Ndagano, B. , Perez-Garcia, B., Rouz, F. S., McLaren, M., Rosales-Guzman, C., Zhang, Y., Mouane, O., Hernandez-Aranda, R. I., Konrad, T. and Forbes, A. (2017) Characterizing quantum channels with non-separable states of classical light. Nature Physics, 13(4), pp. 397-402. (doi: 10.1038/nphys4003)

Abstract

High-dimensional entanglement with spatial modes of light promises increased security and information capacity over quantum channels. Unfortunately, entanglement decays due to perturbations, corrupting quantum links that cannot be repaired without performing quantum tomography on the channel. Paradoxically, the channel tomography itself is not possible without a working link. Here we overcome this problem with a robust approach to characterize quantum channels by means of classical light. Using free-space communication in a turbulent atmosphere as an example, we show that the state evolution of classically entangled degrees of freedom is equivalent to that of quantum entangled photons, thus providing new physical insights into the notion of classical entanglement. The analysis of quantum channels by means of classical light in real time unravels stochastic dynamics in terms of pure state trajectories, and thus enables precise quantum error correction in short- and long-haul optical communication, in both free space and fibre.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Ndagano, Mr Bienvenu
• Authors: Ndagano, B., Perez-Garcia, B., Rouz, F. S., McLaren, M., Rosales-Guzman, C., Zhang, Y., Mouane, O., Hernandez-Aranda, R. I., Konrad, T., and Forbes, A.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Nature Physics
• Publisher: Nature Publishing Group
• ISSN: 1745-2473
• ISSN (Online): 1745-2481
• Published Online: 23 January 2017