Macroscopic quantum states generated by twin-beam systems

Abstract

Nondegenerate parametric oscillation and four-wave mixing generate correlated twin-beams that exhibit squeezing in the intensity difference fluctuations. Using a simple theoretical model for parametric amplification we predict that the twin-beam devices generate macroscopic states that violate Bell’s inequality. In four-wave mixing, or parametric oscillation with an amplitude-squeezed pump, the twin-beams may also exhibit squeezing in the intensity of each beam. We predict that the use of these intensity-squeezed devices is advantageous in the preparation of the macroscopic quantum states. It is also possible to use nondegenerate systems to generate macroscopic superposition (Schrodinger cat) states.