We establish tight upper and lower bounds for the entanglement of formation of an arbitrary two-mode Gaussian state employing the necessary properties of Gaussian channels. Both bounds are strictly given by the entanglement of formation of symmetric Gaussian states, which are simply constructed from the reduced states obtained by partial trace of the original one.

• Received 22 October 2013

DOI:https://doi.org/10.1103/PhysRevA.89.012336