2011/10/31 by D. Yu. Vasylyev, A. A. Semenov, W. Vogel
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/physrevlett.108.220501
published as Phys. Rev. Lett. 108, 220501 (2012) · published version
arxiv created 2012/06/02 · arxiv updated 2012/06/05
Tap-proof long-distance quantum communication requires a deep understanding of the strong losses in transmission channels. Here we provide a rigorous treatment of the effects of beam wandering, one of the leading disturbances in atmospheric channels, on the quantum properties of light. From first principles we derive the probability distribution of the beam transmissivity, with the aim to completely characterize the quantum state of light. It turns out that beam wandering may preserve nonclassical effects, such as entanglement, quadrature and photon number squeezing, much better than a standard attenuating channel of the same losses.