Entanglement and squeezing in continuous-variable systems
Manuel Gessner, Luca Pezzè, Augusto Smerzi · Quantum · 2017
We introduce a multi-mode squeezing coefficient to characterize entanglement in N -partite continuous-variable systems. The coefficient relates to the squeezing of collective observables in the 2N -dimensional phase space and can be readily extracted from the covariance matrix. Simple extensions further permit to reveal entanglement within specific partitions of a multipartite system. Applications with nonlinear observables allow for the detection of non-Gaussian entanglement.