Our recent paper "Entanglement sensitivity to signal attenuation and amplification" has just been published in Physical Review A and selected as an Editors' Suggestion: http://journals.aps.org/pra/highlights
The text is available at the journal website and ArXiv
What is the paper about?
Long-life entangled states for distribution through communication lines
Entanglement is a promising but fragile phenomenon of quantum correlations. Entangled light beams cannot be transmitted too far via optical fibers. The matter is in losses, which cause the signal attenuation, and amplifiers used to reinforce the signal. Both attenuation and amplification introduce noises that affect entanglement and may destroy it. Entanglement lifetime depends on the initial quantum state of light beams, the wavefunction. Usual experiments deal with gaussian states, however, in our paper, we show that they are not optimal. We demonstrate a class of nongaussian states of little energy, which have much longer entanglement lifetime than any gaussian state including that of very high intensity. Suggested states can be amplified with no harm to the entanglement in contrast to gaussian ones whose entanglement cannot survive amplification of 3 dB. Thus, the intelligently encoded entanglement is suitable for distribution through much longer distances than it was thought before.