Quantum Entanglement of Twin Light Beams

Abstract

A detailed quantum entanglement of twin light beams with the same and different frequencies produced by the process of parametric oscillation has been presented. We have described the process of the parametric oscillation with first-order Hamiltonian regardless of whether the twin light beams have the same or different frequencies. According to our study we have the quadrature variance decreases with the amplitude of pump mode  and it approaches to the value of the quadrature variance of  a two-mode vacuum state as cavity damping constant  approaches to 1. In addition to this the degree of entanglement of the cavity modes for the system under consideration increase with the amplitude of the pump mode  and decrease with the cavity damping constant, which implies that the degree of entanglement of twin light beams decreases as quadrature variances approaches to that of a two-mode vacuum state.

Keywords: Quadrature Variance, Entanglement