The simultaneous amplitude and phase damping of two mode squeezed vacuum state
Xiaoyu Chen
Abstract
The Peres-Horodecki criterion of positivity under partial transpose is studied for the simultaneous amplitude and phase damping of a two mode squeezed vacuum state. The criterion turns out to be a necessary and sufficient condition for separability, although the damped state is no longer gaussian. The proof is at the sense of algebraic programming and also perturbation theory. The criterion is stronger than that obtained by the uncertainty principle on the second moments of the partial transposed density matrix.