Emaranhamento tripartite no oscilador paramétrico ótico / Tripartite entanglement in the optical parametric oscillator
AUTOR(ES)
Antonio Sales Oliveira Coelho
DATA DE PUBLICAÇÃO
2009
RESUMO
We present in this work the first experimental verification of entanglement between the, signal, idler and reflected pump beams, generated by an Optical Parametric Oscillator (OPO) above the threshold. Using the criterion of sum of variances, proposed by van Loock and Furusawa, we obtained results that indicate the existence of tripartite entanglement in our system. That is confirmed by applying the criterion of positivity under partial transposition by Peres-Simon (PPT). The observation of this effect, predicted in 2006, faced difficulties related to the existence of a spurious classical noise, introduced by the nonlinear crystal. We have also presented a theoretical model for this that takes into account small fluctuations in the dielectric permittivity of the crystal, associated with vibrations of its lattice. We show how to control and reduce the excess noise in order to achieve conditions for the observation of tripartite entanglement.
ASSUNTO(S)
mecânica quântica quantum information quantum mechanics informação quântica
