Mihai Vidrighin, Tim J. Bartley, Gaia Donati, Xian-Min Jin, Marco Barbieri, W. Steven Kolthammer, Animesh Datta, Ian A. Walmsley
February 13, 2013
Entanglement enhancement is a key task for quantum technologies. This operation performed on states produced by parametric down-conversion sources has been the object of several recent experimental investigations. In particular, conditional preparation by photon-subtraction has been shown to improve the entanglement of these states. Here we analyse the role played by non-Gaussian and Gaussian measurements in more general entanglement concentration operations performed on a pair of two-mode squeezed vacua. We find stringent requirements for achieving an improved entanglement enhancement by measuring jointly these two resource states.