Evolution of twin-beam in active optical media

Abstract

We study the evolution of twin-beam propagating inside active media that may be used to establish a continuous variable entangled channel between two distant users. In particular, we analyze how entanglement is degraded during propagation, and determine a threshold value for the interaction time, above which the state become separable, and thus useless for entanglement based manipulations. We explicitly calculate the fidelity for coherent state teleportation and show that it is larger than one half for the whole range of parameters preserving entanglemenent.

several misprints corrected

References in corpus (4)

• Quantum information processing for a coherent superposition state via a mixed entangled coherent channel
• Using entanglement improves precision of quantum measurements
• Quantum key distribution with bright entangled beams
• Improving quantum interferometry by using entanglement (to take a decision you'd better use entanglement)

Cited by in corpus (8)

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• Continuous-variable entanglement dynamics in Lorentzian environment
• Distance and Coupling Dependence of Entanglement in the Presence of a Quantum Field
• Multi-mode entanglement of N harmonic oscillators coupled to a non-Markovian reservoir
• Generalized uncertainty relations and entanglement dynamics in quantum Brownian motion models