Efficient entanglement criteria beyond Gaussian limits using Gaussian measurements

Phys Rev Lett. 2012 Jan 20;108(3):030503. doi: 10.1103/PhysRevLett.108.030503. Epub 2012 Jan 19.

Abstract

We present a formalism to derive entanglement criteria beyond the Gaussian regime that can be readily tested by only homodyne detection. The measured observable is the Einstein-Podolsky-Rosen (EPR) correlation. Its arbitrary functional form enables us to detect non-Gaussian entanglement even when an entanglement test based on second-order moments fails. We illustrate the power of our experimentally friendly criteria for a broad class of non-Gaussian states under realistic conditions. We also show rigorously that quantum teleportation for continuous variables employs a specific functional form of EPR correlation.