We investigate entanglement concentration of continuous-variable Gaussian states by local single-photon subtractions combined with local Gaussian operations. We first analyze the local squeezing-enhanced entanglement concentration protocol proposed very recently by Zhang and van Loock [e-print: arXiv:1103.4500 (2011)] and discuss the mechanism by which local squeezing before photon subtraction helps to increase the entanglement of the output state of the protocol. We next show that a similar entanglement improvement can be achieved by using local coherent displacements instead of single-mode squeezing.
@article{arxiv.1107.2409,
title = {Improving entanglement concentration of Gaussian states by local displacements},
author = {Jaromir Fiurasek},
journal= {arXiv preprint arXiv:1107.2409},
year = {2015}
}
Comments
6 pages, 5 figures, REVTeX4, accepted for publication in Phys. Rev. A