@Misc{ GiaTreGio15, author = { Giacomo De Palma, and Giovannetti, Vittorio and Trevisan, Dario }, title = { Passive states optimize the output of bosonic Gaussian quantum channels }, journal = { }, year = { 2015 }, pages = { }, URL = { http://cvgmt.sns.it/paper/3484/ }, note = { cvgmt preprint} }