title: Role of initial entanglement and non-Gaussianity in the decoherence of photon-number entangled states evolving in a noisy channel.
abstract: We address the degradation of continuous variable (CV) entanglement in a noisy channel focusing on the set of photon-number entangled states. We exploit several separability criteria and compare the resulting separation times with the value of non-Gaussianity at any time, thus showing that in the low-temperature regime: (i) non-Gaussianity is a bound for the relative entropy of entanglement and (ii) Simon's criterion provides a reliable estimate of the separation time also for non-Gaussian states. We provide several evidences supporting the conjecture that Gaussian entanglement is the most robust against noise, i.e., it survives longer than a non-Gaussian one, and that this may be a general feature for CV systems in Markovian channels.
authors.affiliation: Dipartimento di Fisica Teorica, Università degli Studi di Torino, I-10125 Torino, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Allegra
authors.forename: Paolo
authors.initials: P
authors.lastname: Giorda
authors.forename: Matteo G A
authors.initials: MG
authors.lastname: Paris