Transmitting continuous variable entangled states over long distances

Recently, we experimentally proved that, even in presence of strong decoherence, the bi—partite continuous variable entangled state generated by a sub—threshold type—II optical parametric oscillator (OPO) never disentangles. It keeps breaking the limits for some of the entanglement criteria. In this contribution, we extend our previous analysis by focusing on the behaviour, under decohenrece, of two entanglement measures: Logarithmic Negativity (LN) and Entanglement of Formation (EOF).