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The Rochester Conferences on Coherence and Quantum Optics and the Quantum Information and Measurement meeting

Semiclassical entanglement analyses in a non-degenerate parametric oscillator (NDPO)

Daniel B. Erenso, Joshua Dodson, K. Fesseha

Published Jan 1, 2013• 0 citations
Publisher

Abstract

The entanglement of the intracavity photons in subthreshold NDPO coupled to a squeezed vacuum is studied using the von-neumann entropy (VNE). The VNE is calculated in terms of the Q-function representation for the density operator.
DOI
10.1364/cqo.2013.m6.44

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The von-Neumann entropy (VNE), usually expressed in terms of the density operator, isthe mathematical tool to measure the degree of entanglement of a bi-partite system.Applying the solutions of the quantum Langevin equations, the anti-normally orderedcharacteristic function of the intra-cavity photons produced by a non-degenerateparametric oscillator could be calculated. With the help of the resulting characteristicfunction, the Q- function which is then used to calculate the entanglement of the intra-cavity photons using VNE is determined. Moreover, the photon number distribution, themean photon number, the normalized second order correlation function, the intensitydifference, and quadrature variance for the intra-cavity photons produced by a non-degenerate parametric oscillator coupled to a two-mode squeezed vacuum reservoir isdetermined. It was found that when the squeeze parameter increases the entanglement alsoincreases. These show that the entropy entanglement has a direct relation with squeezing.
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