Displacement-enhanced entanglement distillation of single-mode-squeezed   entangled states
  It has been shown that entanglement distillation of Gaussian entangled states by means of local photon subtraction can be improved by local Gaussian transformations. Here we show that a similar effect can be expected for the distillation of an asymmetric Gaussian entangled state that is produced by a single squeezed beam. We show that for low initial entanglement, our largely simplified protocol generates more entanglement than previous proposed protocols. Furthermore, we show that the distillation scheme also works efficiently on decohered entangled states as well as with a practical photon subtraction setup. 
Anders Tipsmark, Jonas S. Neergaard-Nielsen, and Ulrik L. Andersen
quant-ph