We investigate phase-insensitive linear amplification at the quantum limit for single- and two-mode states and show that there exists a broad class of non-Gaussian states whose nonclassicality survives even at an arbitrarily large gain. We identify the corresponding observable nonclassical effects and find that they include, remarkably, two-mode entanglement. The implications of our results for quantum cloning outside the Gaussian regime are also addressed.
@article{arxiv.1009.2306,
title = {Linear amplification and quantum cloning for non-Gaussian continuous variables},
author = {Hyunchul Nha and G. J. Milburn and H. J. Carmichael},
journal= {arXiv preprint arXiv:1009.2306},
year = {2011}
}